all chapters-after format approval-v1

8/12/2019 All Chapters-After Format Approval-V1

1/151

INVESTIGATION OF GAS-SURFACE INTERACTIONS DURING ATOMIC

LAYER DEPOSITION

by

Vikrant R. Rai


2/151

ii

A thesis submitted to the Faculty and the Board of Trustees of the Colorado

School of Mines in partial fulfillment of the requirements for the degree of Doctor of

Philosophy (Chemical Engineering).

Golden, Colorado

Date: ______________ Signed: _________________________

Vikrant R. Rai

Signed: _________________________

Dr. Sumit Agarwal

Thesis Advisor

Golden, Colorado

Date: ______________

Signed: _________________________

Dr. David W. M. Marr

Professor and Head

Department of Chemical Engineering


3/151

iii

ABSTRACT

The smaller-cheaper-better path of the semiconductor industry has always posed a

challenge in the field of thin film depositions, which can only be pursued by a continuous

evolution of materials and technology. Today, devices demand very narrow process

requirements such as contamination levels, atomic-level uniformity, and conformality.

Atomic layer deposition (ALD) is a thin film deposition technique that has evolved and

matured to meet these requirements. However, the inadequate knowledge of underlying

gas-surface interactions that occur during ALD has been an obstacle towards itsdevelopment for better process control and novel applications. This dissertation

approaches the problem with in situ diagnostics to monitor the surface and gas-phase

species consumed or produced during ALD in real time. The research involved setting up

ALD reactors with multiple diagnostic tools, development of new ALD chemistries, and

characterization of deposited films physical and chemical properties. The work mainly

focuses on O3- and O2 plasma-assisted ALD of technologically-relevant metal oxides,

TiO2, Al2O3, and SiO2, studied using a combination of attenuated total reflection Fourier

transform infrared (ATR-FTIR) spectroscopy, quartz crystal microbalance (QCM), and

optical emission spectroscopy (OES). At the time of writing this dissertation, the setup

used to study the deposition of these metal oxides is unique in terms of the capability to

monitor the surface and gas-phase species during ALD.

Overall, we find that the reaction mechanism during deposition of metal oxides

using O3 and O2 plasma are fundamentally different. The surface chemistry involves

carbonates as one of the reactive sites for the chemisorption of the metal precursor as


4/151

iv

compared to H2O-based ALD where only OH groups have been reported. O3 or O2

plasma-assisted combustion of hydrocarbon ligands in the chemisorbed metal precursor

produces CO2and H2O, which simultaneously react on a metal oxide surface to produce

carbonates. These carbonate species are subsequently removed upon dissociative

chemisorption of the metal precursor contributing to metal oxide formation. On the other

hand, formation of OH groups on the surface depends upon the reactivity of H 2O with the

surface-chemisorbed ligands at the temperature of deposition. For O3- and O2 plasma-

assisted ALD of TiO2, carbonates appear as the reactive sites, and are thermally stable to

prolonged exposures of either oxidizer at 150 C. Since, in the case of O3-assisted ALD,the deposition temperature is not within the ALD window for OH group formation, no

OH groups are observed. However, in the case of plasma-assisted ALD, OH groups are

observed due to plasma-assisted activation of H2O generated during the surface reactions,

which can react with the surface hydrocarbon ligands to form OH groups. On the other

hand, for O3- and O2plasma-assisted ALD of Al2O3, the deposition temperature of 150

C lies within the ALD windows for both carbonates and OH groups formation leading to

both the species as the reactive sites. Although the carbonates are thermally stable in both

cases, they readily decomposed upon prolonged plasma exposure making the reaction

mechanism dependent on the oxidizer dose.

In a novel reaction chemistry developed for ALD of SiO2 from 3-aminopropyl

triethoxysilane, H2O, and O3, formates were observed as the reactive sites. The

mechanism proceeded by self-catalytic hydrolysis of ethoxy ligands to produce OH

groups followed by combustion of remaining aminopropyl ligands to produce carbonates

on the surface.


5/151

v

Thus, there are certain common aspects in O3- and O2plasma-assisted ALD, but

the corresponding reaction mechanisms are not universal. Therefore, a detailed

investigation of the surface reactions using in situ diagnostics is invaluable for

developing ALD processes for different material.


6/151

vi

TABLE OF CONTENTS

ABSTRACT ....................................................................................................................... iiiLIST OF FIGURES ............................................................................................................ xCHAPTER 1 Framework and Overview of Research ........................................................ 1

1.1 Thin Film Growth and Atomic Layer Deposition ............................................. 11.1.1 Thermal ALD ........................................................................................... 41.1.2 Plasma-Assisted ALD .............................................................................. 5

1.2 Applications of ALD ......................................................................................... 71.3 Goals and Motivation ........................................................................................ 8

1.3.1 Alternate Oxidizing Agents for ALD of Metal Oxides ........................... 91.3.2 Development of Novel ALD Chemistries .............................................. 11

1.4 Thesis Organization ......................................................................................... 111.5 Brief Insight into the Reaction Mechanism Studies during ALD ................... 13

CHAPTER 2 In Situ Diagnostics for Studying Gas-Surface Reactions during Thermal

and Plasma-Assisted Atomic Layer Deposition ............................................................... 162.1 Introduction ..................................................................................................... 162.2 Experimental Setup .......................................................................................... 19

2.2.1 Surface Analysis Vacuum Chamber ...................................................... 19

2.2.2 In situ ATR-FTIR Spectroscopy Setup .................................................. 19

2.2.3 Internal Reflection Crystal ..................................................................... 212.2.4 Heater for the Internal Reflection Crystal .............................................. 232.2.5 Precursor and Gas Delivery ................................................................... 24


7/151

vii

2.2.6 High throughput ALD reactor ................................................................ 262.2.7 Optical Emission Spectroscopy ............................................................. 272.2.8 Ex Situ Characterization ........................................................................ 28

2.3 Results and Discussion .................................................................................... 282.3.1 Investigation of Surface Reactions during Thermal and Plasma-Assisted

ALD of TiO2using in situ ATR-FTIR Spectroscopy ..................................... 282.3.2 Detection of Reaction Products during Plasma-Assisted ALD of TiO2

using in situ ATR-FTIR Spectroscopy and Optical Emission Spectroscopy . 332.3.3 Ex Situ Characterization of the Deposited TiO2 Films using IR

Spectroscopy, Spectroscopic Ellipsometry, and X-Ray Diffraction ............... 382.4 Conclusions ..................................................................................................... 412.5 Acknowledgements ......................................................................................... 42

CHAPTER 3 Surface Reaction Mechanisms during Ozone-Based Atomic Layer

Deposition of Titanium Dioxide ....................................................................................... 433.1 Introduction ..................................................................................................... 443.2 Experimental .................................................................................................... 453.3 Results and Discussion .................................................................................... 473.4 Acknowledgements ......................................................................................... 53

CHAPTER 4 Surface Reaction Mechanisms during Plasma-Assisted Atomic Layer

Deposition of Titanium Dioxide ....................................................................................... 544.1 Introduction ..................................................................................................... 554.2 Experimental .................................................................................................... 56


8/151

viii

4.3 Results and Discussion .................................................................................... 574.4 Acknowledgements ......................................................................................... 64

CHAPTER 5 Surface Reaction Mechanisms during Ozone and Oxygen Plasma Assisted

Atomic Layer Deposition of Aluminum Oxide ................................................................ 655.1 Introduction ..................................................................................................... 665.2 Experimental .................................................................................................... 685.3 Results and Discussion .................................................................................... 695.4 Conclusions ..................................................................................................... 775.5 Acknowledgements ......................................................................................... 785.6 Supporting Information ................................................................................... 78

CHAPTER 6 Detailed Mechanism of Atomic Layer Deposition of Aluminum Oxide

using an Oxygen Plasma and Ozone ................................................................................. 796.1 Introduction ..................................................................................................... 806.2 Experimental .................................................................................................... 83

6.2.1 Surface Analysis Chamber with in situ ATR-FTIR Spectroscopy Setup

......................................................................................................................... 836.2.2 High Throughput ALD Reactor ............................................................. 86

6.3 Results and Discussion .................................................................................... 87

6.3.1 Reaction Mechanisms during O2Plasma-Assisted ALD of Al2O3........ 87

6.3.2 Reaction Mechanisms during O3-Based ALD of Al2O3...................... 1006.4 Conclusions ................................................................................................... 1076.5 Acknowledgements ....................................................................................... 108


9/151

ix

CHAPTER 7 Mechanism of Self-Catalytic Atomic Layer Deposition of Silicon Dioxide

using 3-Aminopropyl Triethoxysilane, Water, and Ozone ............................................. 1097.1 Introduction ................................................................................................... 1107.2 Experimental .................................................................................................. 1127.3 Results and Discussion .................................................................................. 1147.4 Conclusions ................................................................................................... 1217.5 Acknowledgements ....................................................................................... 1227.6 Supporting Information ................................................................................. 122

RREFERENCES CITED ................................................................................................ 123APPENDIX A ................................................................................................................. 134Supporting Information ................................................................................................... 134

A.1 Supporting Information for Chapter 5 .......................................................... 134A.2 Supporting Information for Chapter 7 .......................................................... 135

APPENDIX B ................................................................................................................. 136Supporting Information ................................................................................................... 136

B.1 Copyright information for Journal of Physical Chemistry C (Chapter 3) .... 136B.2 Copyright information for Journal of Physical Chemistry C (Chapter 4) .... 136B.3 Copyright information for Langmuir (Chapter 5) ......................................... 137


10/151

x

LIST OF FIGURES

Figure 1.1 Schematic of atomic layer deposition................................................................ 3Figure 1.2 Schematic of viscous flow ALD reactor. .......................................................... 5Figure 1.3 Schematic of different plasma source configuration. ........................................ 7Figure 1.4 IR difference spectrum during O3cycle at 150 C showing removal of TTIP

ligands and formation of carbonates reactive sites. The inset shows thesurface reactions occurring during O3cycle. ............................................ 12

Figure 1.5 IR difference spectrum during O3cycle at 150 C showing removal of TTIPligands and formation of carbonates reactive sites. The inset shows thesurface reactions occurring during O3cycle. ............................................ 13

Figure 2.1 Schematic showing the top view of surface analysis chamber equipped with an

in situATR-FTIR spectroscopy setup. The red line shows the IR beampath from FTIR spectrometer to the MCT-A detector. ............................. 20

Figure 2.2 Reflectivity for s- and p-polarized light at the film-crystal interface as afunction of the deposited films refractive index. The inset shows aschematic of TMA chemisorption on a ZnSe IRC.................................... 22

Figure 2.3 Schematic of the high-throughput hot-wall ALD reactor. OES measurementswere also performed on this setup through a quartz window (not shown inthe figure) mounted on one of the flanges of the 6-way cross. ................. 26

Figure 2.4 IR difference spectra for ALD of TiO2using TTIP in conjunction with H2O (a-b), O3(c-d), and an O2plasma (e-f). Each set of IR spectra were recordedat a substrate temperature that was within the ALD window for TTIP andthe particular oxidizer. .............................................................................. 31

Figure 2.5 IR difference spectra for a single TTIP-O2plasma ALD cycle. (a) Spectrumwas collected after a 5-s TTIP cycle. (b) TTIP-chemisorbed surface in (a)was exposed to a 60-s O2plasma while the chamber was isolated from thevacuum pump. Weakly adsorbed CO and CO2were observed due toplasma-assisted combustion of isopropoxy ligands. (c) The chamber wasevacuated to the base pressure followed by a 120-s O2purge. Absorbancedue to weakly adsorbed CO and CO2was diminished. (d) The chamber

was isolated from the vacuum pump without any precursor exposure of thesurface. ...................................................................................................... 34

Figure 2.6 (a) Optical emission spectrum of a pure O2plasma. The dominant emissionlines at 777.40 and 844.50 nm were observed. (b) Optical emissionspectroscopy data showing selected time-resolved emission lines for CO,
http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232690http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232690http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232691http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232691http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232692http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232692http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232693http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232693http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232693http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232693http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232693http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232693http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232693http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232693http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232694http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232694http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232694http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232694http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232694http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232694http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232694http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232694http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232695http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232695http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232695http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232695http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232695http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232696http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232696http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232696http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232696http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232696http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232697http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232697http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232697http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232697http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232698http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232698http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232698http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232698http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232698http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232698http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232698http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232698http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232698http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232698http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232698http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232698http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232698http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232699http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232699http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232699http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232699http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232699http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232699http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232699http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232699http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232699http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232699http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232699http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232699http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232699http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232699http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232699http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232699http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232699http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232699http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232699http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232699http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232700http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232700http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232700http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232700http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232700http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232700http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232700http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232700http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232699http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232699http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232699http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232699http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232699http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232699http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232699http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232699http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232699http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232698http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232698http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232698http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232698http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232697http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232697http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232697http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232696http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232696http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232696http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232695http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232695http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232695http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232694http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232694http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232694http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232693http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232693http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232693http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232692http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232691http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232690


11/151


12/151

xii

concentration on the surface remained unchanged. (d) The chamber wasisolated from the vacuum pump without any precursor exposure of thesurface. No gas-phase species were observed. .......................................... 60

Figure 4.3 XRD data for a TiO2film deposited at 150 C. Anatase is the dominantcrystalline phase. The left inset shows ex situ transmission IR spectrum ofthe deposited film. No significant carbon contamination in the form ofcarbonates was observed. The peak at 440 cm-1 in the IR spectrum wasattributed to anatase. The right inset shows a linear increase in filmthickness with the number of ALD cycles. ............................................... 63

Figure 5.1 IR difference spectra showing the different surface species due to ligand-exchange reactions at 150 C: (a) TMA and (b) O3half-reaction cycles; (c)TMA and (d) O2plasma half-reaction cycles; (e) O2plasma exposure ofsurface in (d) for a longer duration. The exposure times of TMA, O3, andO2plasma half cycles for surface saturation were 15, 300, and 70 s,respectively. .............................................................................................. 70

Figure 5.2 IR difference spectra for a single TMA-O2plasma ALD cycle showing variousgas-phase reaction products and surface species. (a) Spectrum wascollected after 10 s of TMA exposure with the chamber isolated from thepump. (b) Chamber was evacuated to the base pressure followed by a 120-s inert-gas purge. (c) TMA-chemisorbed surface in (b) exposed to an O2plasma for 30 s with the chamber isolated from the pump. (d) IR spectrumcollected after the chamber was evacuated to the base pressure followedby a 200-s O2plasma exposure. The top panel shows the gas-phase CH4and TMA absorbance for comparison with the gas-phase peaks in (a). ... 73

Figure 5.3 Temporal evolution of the integrated absorbance change for CH3(),carbonate (), and OH () stretching vibrations, and Al-O-Al phonons ()during O2plasma exposure of a TMA-chemisorbed surface at 150 C. Thesolid lines are fits to the experimental data. The maximum integratedabsorbance change for each species was normalized to unity. ................. 76

Figure 6.1 Schematic of the surface analysis chamber equipped with in situATR-FTIRspectroscopy. The arrows indicate the IR beam path from the FTIRspectrometer through the IRC to the MCT-A detector. ............................ 83

Figure 6.2 Schematic of the IRC illustrating the total internal reflection of the IR beam at

the film-crystal interface. The chemisorbed species are probed by theevanescent electric field that decays exponentially into vacuum. ............ 85Figure 6.3 Schematic of the high-throughput hot-wall ALD reactor. ............................... 87Figure 6.4 Temporal evolution of the normalized integrated absorbance change for the

CH3stretching vibrations (30002800 cm-1) during the TMA () and O2
http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232707http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232707http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232707http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232707http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232707http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232707http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232707http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232707http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232707http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232708http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232708http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232708http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232708http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232708http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232708http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232708http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232708http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232708http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232708http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232708http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232708http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232708http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232708http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232708http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232708http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232708http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232709http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232709http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232709http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232709http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232709http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232709http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232709http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232709http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232709http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232709http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232709http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232709http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232709http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232709http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232709http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232709http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232709http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232709http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232710http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232710http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232710http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232710http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232710http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232710http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232710http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232710http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232710http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232710http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232710http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232710http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232710http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232711http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232711http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232711http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232711http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232711http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232711http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232712http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232712http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232712http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232712http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232713http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232713http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232714http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232714http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232714http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232714http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232714http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232714http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232714http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232714http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232714http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232714http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232714http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232714http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232713http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232712http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232712http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232712http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232711http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232711http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232711http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232710http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232710http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232710http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232710http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232710http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232709http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232709http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232709http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232709http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232709http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232709http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232709http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232709http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232709http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232708http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232708http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232708http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232708http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232708http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232708http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232707http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232707http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232707http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232707http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232707http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232707


13/151

xiii

plasma () half-reaction cycles at a substrate temperature of 150 C. Thesolid lines represent exponential fits correspond to first-order reactionkinetics. The inset shows the integrated area in the 30002800 cm-1regionfor the CH3stretching vibrations during the TMA cycle, recorded at 15 sof TMA exposure. ..................................................................................... 88

Figure 6.5 IR difference spectrum showing (a) TMA half-reaction cycle for PEALD ofAl2O3at 150 C. (b-f) Temporal evolution of the surface species during O2plasma exposure of theCH3-terminated surface, indicating the formationand subsequent consumption of metal carbonates in the 18001350 cm-1region. ....................................................................................................... 89

Figure 6.6 IR difference spectra for two complete ALD cycles at 150 C. (a) The surfacewas exposed to TMA for 15 s followed by a 180-s inert-gas purge. (b) TheTMA-chemisorbed surface in (a) was exposed to O2plasma for 10 s, justsufficient to completely combust the methyl ligands. (c) The carbonates in(b) were completely removed in the subsequent TMA exposure cycle (see18001350 cm-1region). (d) A 70-s O2plasma exposure of the surface in(c) completely removed the carbonates that appeared in (b) after 10 s. ... 92

Figure 6.7 IR difference spectra for a single TMA-O2plasma ALD cycle showing variousgas-phase and surface species. (a) Spectrum was collected after 10 s ofTMA exposure with the chamber isolated from the pump. Surfacechemisorbed TMA along with gas-phase TMA and CH4were observed inthis spectrum. (b) Chamber was evacuated to the base pressure followedby a 120-s inert-gas purge. The absorbance due to the gas-phase specieswas eliminated in the spectrum. (c) Gas-phase TMA along with a smallconcentration of the CH4, which may have been generated due to the

presence of adventitious H2O in the chamber. (d) TMA-chemisorbedsurface in (b) exposed to an O2plasma for 30 s with the chamber isolatedfrom the pump. Weakly chemisorbed CO2generated due to plasma-assisted combustion ofCH3ligands was observed. (e) IR spectrumcollected after the chamber was evacuated to the base pressure followedby a 200-s O2plasma exposure. The top spectrum shows absorbance dueto gas-phase CH4for comparison with the gas-phase peaks in (a), (c), and(d). ............................................................................................................. 94

Figure 6.8 Temporal evolution of the integrated absorbance change for CH3(),carbonates (), OH (), and Al-O-Al phonons () during O2plasma

exposure of a TMA-chemisorbed surface at 150 C. The solid lines areexponential fits to the experimental data. The maximum integratedabsorbance change for each species was normalized to unity. ................. 97

Figure 6.9 (a) IR difference spectra for one complete TMA-O2plasma ALD cycle at 70,150, 200 C. (b) The GPC and refractive index at 650 nm for O2plasma-assisted ALD over the substrate temperatures of 70-200 C. ................... 99
http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232719http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232715http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232715http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232715http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232715http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232715http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232715http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232715http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232715http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232715http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232715http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232715http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232715http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232715http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232715http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232715http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232715http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232715http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232715http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232715http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232715http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232715http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232715http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232716http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232716http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232716http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232716http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232716http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232716http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232716http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232716http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232716http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232716http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232716http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232716http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232716http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232716http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232716http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232716http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232718http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232718http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232718http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232718http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232718http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232718http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232718http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232718http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232718http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232718http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232718http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232718http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232718http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232718http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232718http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232719http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232719http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232719http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232719http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232719http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232719http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232719http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232719http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232719http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232719http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232719http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232718http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232718http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232718http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232718http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232718http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232717http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232716http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232716http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232716http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232716http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232716http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232716http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232716http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232715http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232715http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232715http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232715http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232715


14/151

xiv

Figure 6.10 Integrated absorbance change calculated forCH3stretching vibrations(30002800 cm-1) during TMA () and O3() half-reaction cycles at 150C. The integrated absorbance change was normalized with its saturatedvalue. The solid line for TMA represents exponential fit corresponding tofirst order kinetics. The dashed line for O3is not a fit, but is shown to

guide the eye. .......................................................................................... 101

Figure 6.11 IR difference spectra showing the (a) TMA and (b) O3half-reaction cycles at150 C. A one-to-one exchange of surface species is evident in thesespectra. .................................................................................................... 103

Figure 6.12 IR difference spectra for a single TMA-O3ALD cycle showing various gas-phase reaction products and surface species. (a) Spectrum recorded afterexposing the surface to TMA for 10 s followed by inert gas purge for 180s. (b) IR spectrum corresponding to only gas-phase and weakly adsorbedsurface species during the TMA cycle in (a). (c) The TMA-chemisorbedsurface in (a) exposed to a 30-s O3cycle followed by a 120-s inert gaspurge. (d) IR peaks corresponding to gas-phase and weakly adsorbedsurface species during O3cycle in (c). .................................................... 104

Figure 6.13 IR difference spectra showing the O3and the subsequent TMA half-reactioncycles at 70, 150, and 200 C. ................................................................. 106

Figure 7.1 Schematic of the surface analysis chamber equipped with in situ ATR-FTIRspectroscopy. The red line shows the beam path for the He-Ne laser fromthe FTIR spectrometer through the IRE to the MCT-A detector. ........... 112

Figure 7.2 IR difference spectra recorded during APTES, H2O, and O3reaction cycles at

150 C. Vibrational modes for different surface species during the ligand-exchange reactions are indicated. Inset shows the CHx(x= 2,3) stretchingregion for APTES and combined H2O and O3cycles. ............................ 117

Figure 7.3 Schematic showing the surface reactions during ALD of SiO2from APTES,H2O, and O3. The dotted lines represent possible hydrogen-bondingconfigurations. ........................................................................................ 121

Figure A.1 Schematic showing mechanism for O3and O2plasma-assisted ALD of Al2O3.................................................................................................................. 134

Figure A.2 IR difference spectrum recorded after the O3cycle showing the asymmetricand symmetric Si-O-Si stretching vibrations in SiO2at 150 C. Thespectral region in 1300950 cm-1was fitted with 4 Gaussian bandscentered at 1056, 1160, 1200, and 1245 cm-1. ........................................ 135
http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232720http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232720http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232720http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232720http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232720http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232720http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232720http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232720http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232720http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232720http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232720http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232720http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232720http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232720http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232720http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232720http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232720http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232720http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232720http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232720http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232720http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232720http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232720http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232721http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232721http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232721http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232721http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232721http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232721http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232722http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232722http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232722http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232722http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232722http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232722http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232722http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232722http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232722http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232722http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232722http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232722http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232722http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232722http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232722http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232723http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232723http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232723http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232723http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232723http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232724http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232724http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232724http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232724http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232725http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232725http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232725http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232725http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232725http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232725http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232725http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232725http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232725http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232725http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232725http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232725http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232725http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232725http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232725http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232725http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232725http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232726http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232726http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232726http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232726http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232726http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232726http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232726http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232726http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232726http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232726http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232727http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232727http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232727http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232727http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232727http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232727http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232727http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232727http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232727http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232727http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232727http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232728http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232728http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232728http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232728http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232728http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232728http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232728http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232728http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232728http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232728http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232728http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232728http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232728http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232728http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232728http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232728http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232728http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232728http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232728http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232727http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232727http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232726http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232726http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232726http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232725http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232725http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232725http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232725http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232724http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232724http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232724http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232723http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232723http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232722http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232722http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232722http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232722http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232722http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232722http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232722http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232722http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232721http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232721http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232721http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232720http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232720http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232720http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232720http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232720http://e/Dropbox/Research/Thesis/Thesis%20combined/All%20chapters-Correction%202.docx%23_Toc290232720


15/151


16/151

2

properties of these thin films have to be suitably tailored generally using a vapor

deposition based technique.[20-21]

Synthesis of thin films for present-day applications, especially from a

miniaturization and process integration perspective, is particularly challenging due to

strict process requirements such as low deposition temperature and contamination level,

atomic-level uniformity over large areas, and excellent conformality on the underlying

substrate.[22-26] Therefore, new thin film materials and deposition methods are actively

explored. Among the different thin film deposition techniques, atomic layer deposition

(ALD) has recently emerged as a potential deposition method for advanced devicestructures.[24-25,27] ALD is based on sequential self-limiting gas-solid reactions. It is a

special modification of chemical vapor deposition (CVD) with a distinct feature that

alternate exposures of gaseous precursors are used to deposit a fraction of a monolayer in

one complete reaction cycle. The process is then repeated to deposit the film layer-by-

layer, thus, providing digital control over the film thickness. Figure 1.1 shows a

schematic of the ALD process to deposit binary compounds such as metal oxides and

metal nitrides where each individual step is referred to as a half-reaction cycle. In the first

half-reaction cycle, a pre-functionalized surface is exposed to precursor A, which

exchanges ligands with the surface functional groups during its chemisorption to produce

a volatile reaction product that desorbs from the surface. Chemisorption of precursor A

on the surface consumes all the available functional sites and produces new functional

groups which are not reactive towards A, thus, limiting the surface coverage to a sub-

monolayer equivalent of A. The volatile reaction product along with the excess precursor

are purged from the reaction chamber using an inert gas. After the purge step, the surface


17/151

3

is exposed to precursor B, which again chemisorbs in a self-limiting manner and restores

the active functionality for chemisorption of precursor A in the subsequent half-reaction

cycle. This set of reactions constitutes one complete ALD cycle which results in the

deposition of sub-monolayer of the material characterized as growth per cycle (GPC).

Each half-reaction cycle is separated by a purge step to avoid any gas-phase CVD-like

reactions between the two precursors.

The precursors used in ALD should be volatile and remain thermally stable at the

deposition temperature.[23] Unlike CVD, under ideal film deposition conditions, the

GPC remains independent of substrate temperature, reactor geometry, and precursor

dosage (after saturation). This temperature window over which the GPC remains

independent of the substrate temperature is known as the ALD window. Within this

temperature window, ligand-exchange reactions of the precursors with the surface are

Figure 1.1 Schematic of atomic layer deposition.


18/151

4

complete during each half-reaction cycle.[22-24] The GPC is generally limited by steric

hindrance due to the chemisorbed ligands of the precursor.

The surface reactions in an ALD process can be either driven thermally or by

plasma-generated high-energy radicals, which lead to classification of ALD processes

into two major category: thermal ALD and plasma-assisted ALD, also shown in Figure

1.1ure 1 for the case of Al2O3 deposition from trimethyl aluminum and H2O or an O2

plasma.

1.1.1Thermal ALD

Historically, the ALD process was developed in early 80s under the name atomic

layer epitaxy (ALE) by Suntola and co-workers who demonstrated layer-by-layer

growth of metal sulfides, metal oxides, and compound semiconductors.[28-29] Since

then, thermal ALD is the most extensively studied approach to ALD. While the process is

well-suited for binary compounds such as metal oxides and metal nitrides,[22-23] in

some cases, it has also been demonstrated for depositing single elements such as W.[30-

32] However, most single elements cannot be deposited using this approach.[33] The

whole thermal ALD processing cycle can essentially be conceived as a series of gaseous-

precursor-exposure cycles where the adsorption kinetics during each half-reaction cycle

is driven by heating the substrate, which provides the necessary activation energy for the

dissociative chemisorption of the molecular precursors. Figure 1.2 shows the most

commonly used viscous flow type reactor, where the direction of flow of the precursors is

parallel to the substrate, which itself is heated by the reactor walls via convection and

radiation.[34-35] Numerous metal oxides and nitrides such as Al2O3,[9-10,16,22,34-43]


19/151


20/151

6

plasma phase, the process only moderately depends on thermal activation of the surface

reactions and, therefore, offers several advantages that are listed below.[69]

Improved material properties including higher film density, lower impurity levels,

and better control of film composition and microstructure.[70-71]

Deposition at reduced substrate temperatures as the reactivity of the plasma

species widens the ALD temperature window towards the low-temperature

side.[70-72]

Increased choice of precursors and materials that can be deposited, including

high-quality single-elements (metals) that are difficult to obtain by thermal ALD.

Good control over the film stoichiometry by tailoring the plasma step as well as

the possibility of co-doping during the plasma step.[73]

Increased GPC as well as reduced purging steps, especially at low substrate

temperatures.[74-75]

Enhanced process versatility due to the possibility of in situ substrate

conditioning, plasma densification, nitridation, etc.[70,72,76-77]

However, plasma-assisted ALD limits conformal coverage in high-aspect-ratio

trenches due to the wall recombination of reactive species before reaching deep inside the

trench.

Depending upon the location of the discharge with respect to the substrate,

plasma-assisted ALD can be classified into two broad categories: direct and indirect

plasma-assisted ALD. A schematic of the corresponding hardware configurations is

shown in Figure 1.3. In case of direct plasma ALD, the substrate is in direct contact with

the reactive species generated in the plasma. A common plasma source configuration is a


21/151

7

capacitively-coupled plasma, which involves two parallel plates separated by a distance

of ~1-5 cm. Radio-frequency power is used to drive plasma over a pressure range 1-100

mTorr. The substrate is generally placed on the grounded electrode. For uniform

distribution of the precursor and the plasma species, a showerhead gas distributor is used

to supply the process gases. In case of indirect or remote plasma-assisted ALD, the

substrate is kept at a distance of typically few tens of centimeters from the plasma source,

and the reactive species diffuse through the plasma to the substrate. A common hardware

configuration is an inductively coupled plasma, where rf power is applied to a helical Cu

coil placed around a quartz tube. The plasma can again be operated over the pressurerange of 1-1000 mTorr.

1.2Applications of ALDALD has numerous applications, especially in electronic devices, due to the

Figure 1.3 Schematic of different plasma source configuration.


22/151

8

ability to deposit uniform films over large areas. In the early 1980s, ALD was first

developed for the fabrication of polycrystalline ZnS:Mn and insulator films for thin film

electroluminescent flat panel displays.[5,28-29] For dynamic random access memory

applications based on the stacked capacitor approach, ALD of Al2O3 and TiN delivers

better process integration and a low thermal budget compared to metal-organic CVD and

sputtering.[62,78-79] A nanohybrid superlattice of self-assembled organic layers, Al2O3,

and TiO2 deposited using molecular layer deposition and ALD are used in flexible

organic light emitting diodes (OLED).[3] Thin films of Al2O3are good diffusion barriers

for H2O and O2, and are used in protective packaging of liquid crystal displays andOLEDs. [36,41,76] Recently, ALD has also been used for coating magnetic read and

write heads of hard disk drives.

ALD also possesses the unique ability to template different materials, which can

lead to the development of advanced nanostructures. For instance, Perez et al. reported

fabrication of HfO2nanotubes from an anodized aluminum oxide template.[80] Similarly,

low-temperature ALD of Al2O3was used to coat a replicate a butterfly wing , which may

be used as a building blocks in photonic integrated circuits.[15] Thus, ALD can be

considered as a technique that enables numerous technologies by offering process

flexibility over wide range of processing parameters.

1.3Goals and MotivationIn ALD, the surface reaction mechanisms during each half-reaction cycle play a

very important role in determining the physical, chemical, and electrical properties of the

material being deposited. Therefore, an in-depth understanding of these surface processes


23/151


24/151

10

TMA cycle:

Al-OH*+ AlCH33 Al-O-AlCH32* + CH4

H2O cycle:

Al-O-AlCH3*+ H2O AlOH

*+ CH4

In the above chemical reactions, the asterisks represent surface chemisorbed

species.

While H2O-based ALD processes are versatile, the presence of H2O in the process

environment can often be incompatible with cold-wall reactors where it desorbs slowly

during the subsequent metal precursor half-reaction cycle leading to CVD-like reactions.

Use of hot-wall reactors can minimize such problems, however, H2O is still difficult to

remove from high-aspect-ratio nanostructures. To address this issue, other non-aqueous

oxidizers such as O2,[87-88] O2 plasmas,[77,89-90] and more recently, O3[82,91-92]

have been explored. These oxidizers offer several advantages such as ease of generation,

higher reactivity, and capability to deposit relatively contamination-free films at

relatively low substrate temperatures compared to H2O.[69,77,82,87-92] However, only a

very small fraction of these metal precursors have been used in conjunction with non-

aqueous oxidizers, and the reaction mechanisms that lead to film deposition are not

completely understood. This motivated us to explore the surface reactions during O3- and

O2plasma -assisted ALD of metal oxides. Specifically, we have investigated the surface

reaction mechanisms during ALD of technologically important high-metal oxides such

as TiO2 and Al2O3, using O3 and O2 plasma as oxidizers. Details of this work are

presented in Chapters 2-6.


25/151

11

1.3.2Development of Novel ALD ChemistriesNumerous metal oxides and nitrides have been deposited using ALD following a

binary reaction sequence. However, a few metal oxides and single elements such as

metals either require a very high temperature or are incompatible with half-reaction

cycles for deposition. SiO2, which is one of the most widely used dielectric materials in

the semiconductor industry, remains as one of the most challenging materials to deposit

via ALD. Recently, Bachmann et al. reported self-catalytic ALD of SiO2at 150 C using

3-aminopropyl triethoxy silane (APTES), H2O, and O3, but only speculated on the

reaction mechanism.[45]

This motivated us to investigate the reaction mechanism during

all chapters-after format approval-v1

Documents