ee503 topic 2 hoo

7212019 EE503 Topic 2 Hoo

httpslidepdfcomreaderfullee503-topic-2-hoo 122

89

Topic 2

EE503

IC Fabrication amp Packaging Technology

983120983154983141983152983137983154983141983140 983138983161983098 983109983150983143983154983086 983112983151983151 983117983151983159 983112983141983150983143



89

Tens or hundreds of identical chips (die) are fabricated

simultaneously on a silicon wafer (substrate)

Wafer Size (refer ro diagram)

The cost of fabricating ICs drops dramatically ifthere are more chips on a wafer

The number of chips on a wafer variesdepending on the type of product and thelevel of integration on the chip



89

Silicon substrate

draindraindraindrain

Silicon substrate

encapsulation

Metal

Insulator

Active layers

polysilicon

Fabrication of the semiconductor devices occurs

only in the first few microns of the silicon nearthe wafer surface

The bulk of the silicon wafer thickness is to givethe wafer adequate rigidity during processing

Stages of IC Fabrication Fabrication of microchips involves five general

stages of manufacturing



89

The primary semiconductor material used tofabricate microchips is silicon

The natural silica (sands) must be purified

into an extremely clean silicon material

Pure silicon is required to minimize

microdefects at the atomic level of the silicon

that are detrimental to semiconductor

performance

The highly refined silicon used for waferfabrication is termed semiconductor-grade

silicon (SGS) or electronic-grade silicon



89

Steps to Obtaining SemiconductorSteps to Obtaining SemiconductorSteps to Obtaining SemiconductorSteps to Obtaining Semiconductor----Grade Silicon (SGS)Grade Silicon (SGS)Grade Silicon (SGS)Grade Silicon (SGS)

Step Description of Process Purity Rate

1 Produce metallurgical-grade silicon

(MGS) by heating silica with carbon

SiC (s) + SiO2 (s) Si (l) + SiO(g) + CO (g)

98

2 Purify MGS through a chemical reaction to produce

a silicon-bearing gas of trichlorosilane (SiHCl3)

Si (s) + 3HCl (g) SiHCl3 (g) + H2 (g) + heat

-

3 Using the Siemens process SiHCI3 and H2 react

to produce pure semiconductor- grade silicon

(SGS)

2SiHCl3 (g) + 2H2 (g) 2Si (s) + 6HCI (g)

999999999

Semiconductor-grade silicon used to

fabricate semiconductor devices have

ultrahigh purity but it must also have a near-

perfect crystal structure

This condition is necessary to avoid electrical

and mechanical defects that are detrimental

to device performance



89

Amorphous materials are noncrystalline solids lackrepetitive structure and demonstrate structuraldisorder at atomic level (ex Plastic) ndash not suitablefor the silicon used in wafers to fabricatesemiconductor devices

A crystal is a solid material with ordered andrepetitive structure of many atoms - suitable tofabricate semiconductor devices

Amorphous Structure



89

Polycrystal and Monocrystal (Single Crystal) StructuresPolycrystal and Monocrystal (Single Crystal) StructuresPolycrystal and Monocrystal (Single Crystal) StructuresPolycrystal and Monocrystal (Single Crystal) Structures

If the unit cells for a crystal structure are not in a regular

arrangement then the material is a polycrystal Ex SGS If the unit cells are neatly arranged in a three-dimensional

repeatable manner then the crystal structure ismonocrystal (single crystal)

Semiconductor wafer processing requires a puremonocrystalline silicon structure

It provides the desirable electrical and mechanicalproperties necessary for silicon wafer processing andperformance

Polycrytalline Structure Monocrytalline Structure

Wafer PreparationWafer PreparationWafer PreparationWafer Preparation

The cylindrical single-crystal ingot (also

called a boule) must undergo a series of

process steps to transform it into wafers

for semiconductor manufacturing



89

Crystal growth is the process of converting

the polysilicon chunks of semiconductor-

grade silicon into a large monocrystal of

silicon

Over 85 of all silicon crystals are grown

according to the Czochralski (CZ) method

The Czochralski growth of a silicon

monocrystal involves the transformation of

molten SG silicon liquid into a solid silicon

ingot

SINGLE CRYSTAL SILICON GROWTHSINGLE CRYSTAL SILICON GROWTHSINGLE CRYSTAL SILICON GROWTHSINGLE CRYSTAL SILICON GROWTH



89

To grow a silicon ingot chunks of SG silicon(polycrystal) are placed in a quartz crucible alongwith small amounts of dopant (boron to create p-typesilicon phosphorus to make n-type silicon)

The crucible of silicon is heated in the furnace usingheating elements

Czochralski (CZ) methodCzochralski (CZ) methodCzochralski (CZ) methodCzochralski (CZ) method

A crystal seed is attached to a crsytal pullermechanism

The seed is placed at the surface of the melt and isslowly drawn away while rotating in a direction that isopposite to the rotation of the crucible

Liquid from the melt is raised with it by surfacetension and slowly solidifies downward

As the seed is steadily pulled out of the melt androtated a single crystal ingot formed



89

FloatFloatFloatFloat----Zone (FZ) MethodZone (FZ) MethodZone (FZ) MethodZone (FZ) Method

A bar of doped polycrystal is

placed in the grower A monocrystal seed is attached

to one end of the bar

An RF coil applies heat at thecontact area of the bar and seedfor about 30 minutes

This monocrystal (single crystal)growth process progresses alongthe bar as the heater is movedalong its axis

FZ method produces high-puritysilicon with lower oxygen contentcrystals

FZ typically makes smaller-diameter wafers than the CZprocess

Crystal Trimming amp Diameter GrindCrystal Trimming amp Diameter GrindCrystal Trimming amp Diameter GrindCrystal Trimming amp Diameter Grind

End Removal

to cropped off the two ends of the ingot

check dopant uniformity throughout the

ingot

Diameter Grinding

to create precise diameter control and

roundness of the ingot

Critical for automated wafer-handling steps

in wafer fabs



89

Flat Grinding Flat Grinding Flat Grinding Flat Grinding Wafer Flat - to identify the crystal structure and to orient the wafer

Wafer SlicingWafer SlicingWafer SlicingWafer Slicing Slicing of wafer is being done with an

Internal Diameter Saw or Wire Saw

The thickness of the wafer is carefully

controlled at 75 plusmn 25 microns

Wafer thickness is crucial to withstand

high temperature and mechanical

shocks during semiconductor fabrication

process

Wafer Lapping Wafer Lapping Wafer Lapping Wafer Lapping a mechanical two-sided lapping operation to

remove damage left by slicing and to achieve

a high degree of parallelism and flatness of

the wafer

Edge ContourRounding Edge ContourRounding Edge ContourRounding Edge ContourRounding A polished wafer edge grind is applied to the

wafer to contour a smooth radius on the edge of

the wafer

before or after lapping

A smooth edge radius is important to minimize

chipped edges which cause edge dislocation

growth during thermal process



89

EtchingEtchingEtchingEtching Wafers undergo a wet chemical etch process to

remove the damage and contamination on thewafer

about 20 microns of silicon wafer surface is

removed to ensure that all damage is removed

PolishingPolishingPolishingPolishing Double-sided Polishing (DSP) with Chemical

Mechanical Planarization (CMP) to achieve a

smooth wafer surface with a high degree offlatness

Wafer InspectionEvaluationWafer InspectionEvaluationWafer InspectionEvaluationWafer InspectionEvaluation Prior to packaging the wafer it is inspected for

quality criteria that are specified by the customer

Ex surface defects such as particulate

contamination and stains



89

Epitaxial LayerEpitaxial LayerEpitaxial LayerEpitaxial LayerEpitaxial LayerEpitaxial LayerEpitaxial LayerEpitaxial Layer

Epitaxial layer (also known as epilayer ) A layer of the same monocrystalline structure deposited on

the surface of the silicon wafer with control over the

doping type or concentration

Thickness 05 to 5 microm

Ex n-type epilayer on a p-type wafer

Ex p-type epilayer (low concentration ) on a p-type wafer

Importance of Epitaxial LayerImportance of Epitaxial LayerImportance of Epitaxial LayerImportance of Epitaxial LayerImportance of Epitaxial LayerImportance of Epitaxial LayerImportance of Epitaxial LayerImportance of Epitaxial Layer

To improve performance in bipolar transistors and

integrated circuits

Bipolar transistors - high breakdown voltage in the pn

junction low collector resistance high speed at

moderate currents

CMOS ICs - minimizes latchup problems



89

Epitaxial Growth MethodsEpitaxial Growth MethodsEpitaxial Growth MethodsEpitaxial Growth MethodsEpitaxial Growth MethodsEpitaxial Growth MethodsEpitaxial Growth MethodsEpitaxial Growth Methods

Three methods used to grow epitaxial

layers on silicon wafers for IC production

are

1 Vapor-phase epitaxy (VPE)

2 Metalorganic CVD (MOCVD)

3 Molecular-beam epitaxy (MBE)

VaporVaporVaporVapor----Phase Epitaxy (VPE)Phase Epitaxy (VPE)Phase Epitaxy (VPE)Phase Epitaxy (VPE) The most common method used for silicon epitaxial

growth

Silicon VPE is achieved by passing gas compounds of

the desired chemicals over single-crystal silicon wafers

that are heated from 800 to 1150degC

The heat from the high temperature provides the

energy necessary to drive the chemical reactions

which take place on the surface of the wafer



89

Metalorganic CVD (MOCVD)

MOCVD is a form of VPE

at low temperature

As with the VPE process compounds of the desired

materials are transported to a heated substrate where

the complex chemical reaction takes place on the wafer

surface

not typically used for silicon epitaxy

important for the controlled deposition of ultra-thin

doped or undoped semiconductor such as gallium

arsenide (GaAs) primarily used for lasers light-emittingdiodes (LED)

MolecularMolecularMolecularMolecular----Beam Epitaxy (MBE)Beam Epitaxy (MBE)Beam Epitaxy (MBE)Beam Epitaxy (MBE)

MBE takes place under conditions of high vacuum

temperature range is between 500 to 900degC

Most silicon MBE systems produce silicon atoms for the

epitaxial reaction through the evaporation of silicon with

an electromagnetically focused electron beam source

The beam of silicon atoms leaving the silicon source

travels through the evacuated chamber without

collisions and deposits on the single-crystal wafersurface



89

Characteristics of wafer for IC FabricationCharacteristics of wafer for IC FabricationCharacteristics of wafer for IC FabricationCharacteristics of wafer for IC FabricationCharacteristics of wafer for IC FabricationCharacteristics of wafer for IC FabricationCharacteristics of wafer for IC FabricationCharacteristics of wafer for IC Fabrication

Important silicon wafer quality requirements are

Physical dimensions

Flatness

Microroughness

Oxygen content

Crystal defects

Particles

Bulk resistivity

The suppliers of silicon wafers must control their

wafer quality by performing ingot and waferquality inspections to demonstrate that quality

specifications are met

Physical Dimensions measurements such as diameter thickness

location and size of orientation flat (or notch) and

wafer deformation

Flatness

most critical wafer parameters because of

photolithography process

Wafer flatness is the linear thickness variation

across the wafer

Typical flatness specifications for site flatness are

008 to 012microm



89

Microroughness

Surface microroughness measures the peaks and valleys height

deviation on the wafer surface and is specified in units of

nanometers

Surface microroughness is important to avoid breakdown of very

thin dielectric films during device fabrication

Wafers undergo a lapping step followed by an etching step to

remove surface microroughness

Oxygen Content

Small amounts of oxygen can have beneficial gettering effects

which can tie up contaminants in the wafer

However excessive oxygen in the silicon ingot can affect the

mechanical and electrical properties of the silicon

increase in the leakage current at the pn junction and also to

increased MOS leakage

Crystal Defects the current requirement is for the number of

crystal defects per square centimeter to be less

than 1000

Particles

The number of surface particles are controlled on

a wafer to minimize yield loss during wafer

fabrication

minimize the generation of particles during wafer

processing followed by effective cleaning stepsto remove particles

A typical wafer-cleanliness specification is to have

less than 013 particles per square centimeter

(1300 particles per square meter) of wafer

surface area on a 200-mm wafer



89

Bulk Resistivity

The resistivity of the bulk silicon ingot depends on

the density of the dopant material that was addedto the silicon melt prior to crystal growth

Adding dopants to silicon is to decrease its

resistivity due to increased carrier mobility

During crystal growth process different

temperature at the center of the ingot and

decreases toward the outer edge produces

variations in the radial doping concentration of the

ingot

The bulk silicon ingot is checked for correctresistivity and uniformity after the ends of the ingot

have been removed

Reasons For Larger Ingot DiametersReasons For Larger Ingot DiametersReasons For Larger Ingot DiametersReasons For Larger Ingot Diameters

Silicon ingot diameters have increased from less than

25 mm (1950s) to 300 mm (recent)

The main reason for increasing ingot diameter is due to

wafer fabrication cost

Larger-diameter wafers have a greater surface area for

chips More chips that can be produced from a single

wafer



89

Larger wafers means more chips per wafer leading to

improved equipment productivity due to economies of

scale for less handling per chip and less processing

time per chip It is estimated that conversion to a 300-mm wafer diameter will reduce the fabrication cost per

chip by approximately 30 through equipment

utilization improvements

Another benefit from larger-diameter wafers is that fewer

chips are near the edge of the wafer which translates

into higher production yield

Ultimately cost savings will be the major factor that

drives the industry toward a larger wafer diameter

Sources of Contamination

Seven sources of contamination in a wafer

fabrication facility are

1 Air

2 Humans

3 Facility

4 Water

5 Process chemicals

6 Process gases

7 Production equipment



89

1 Air

The most fundamental concept of a cleanroom is the

control of particles in the wafer fab air small airborne aerosol particles float and remain in the

air depositing on wafers as contamination and

creating killer defects

2 Humans

People are the greatest sources of contamination in a

cleanroom

Particles come from hair clothes dead skin

excessive movements talking coughing and

sneezing are damaging to semiconductors

Average person sheds over 10000000 particles perminute of 03 microm size and larger

Require cleanroom garment

3 Facility3 Facility3 Facility3 Facility

A simplified diagram of the air handling system in a wafer

fab cleanroom



89

Air Filtering

Air enters the cleanroom through special particulate filters

in the ceiling and passes with laminar flow to the floorand into the recirculation air system to return back to the

air filtering system with makeup air An exhaust system

is used to remove undesirable heat and chemicals

Temperature and Humidity

temperature control in a class 1 at 03 microm cleanroom is

68 plusmn 05deg

Relative humidity (RH) 40 +-10 - important because

of its contribution toward corrosion

Electrostatic Discharge Static-dissipative cleanroom

materials ESD grounding Air ionization

3 Water To manufacture semiconductors a high quality

ultrapure deionized (DI) water (sometimes referred

to as UPW) is required primarily in the chemical

wafer cleaning solutions and as a postclean rinse

Free from Dissolved ions Organic materials

Particulates Bacteria Silica and Dissolved oxygen

4 Process Chemicals Process Gases

Liquid chemicals used in semiconductor processing

must be free of contamination for successful device

yield and performance Filters are used to prevent chemical degradation

during delivery or to maintain chemical purity

during a recirculation step

Gases pass through purifiers and gas filters to

remove impurities and particles



89

5 Production Equipment Many wafer fabrication operations occur in a

vacuum which requires special design

considerations to avoid contamination

Since equipment automation means fewer

humans interacting with the product there is

less concern about particles from humans and

more emphasis on reducing particles from

equipment

CleanroomCleanroomCleanroomCleanroom The class number designates the air quality inside a

cleanroom by defining the particle size and density in

the cleanroom air

US Federal Standard 209E Examples

Class 10 at 02 microm - a maximum of 75 particles per

cubic foot at 02 microm or larger





89

Tens or hundreds of identical chips (die) are fabricated

simultaneously on a silicon wafer (substrate)

Wafer Size (refer ro diagram)

The cost of fabricating ICs drops dramatically ifthere are more chips on a wafer

The number of chips on a wafer variesdepending on the type of product and thelevel of integration on the chip



89

Silicon substrate


Silicon substrate

encapsulation

Metal

Insulator

Active layers

polysilicon








89







performance





89






98




-



(SGS)


999999999










89



Amorphous Structure



89















89




silicon






ingot




89










89










End Removal



ingot

Diameter Grinding




in wafer fabs



89









process




the wafer



the wafer







89














89










integrated circuits



moderate currents




89




are





growth









89



at low temperature




surface
















89



Physical dimensions

Flatness

Microroughness

Oxygen content

Crystal defects

Particles

Bulk resistivity






wafer deformation

Flatness




across the wafer


008 to 012microm



89

Microroughness



nanometers





Oxygen Content









than 1000

Particles



fabrication









89

Bulk Resistivity









ingot


have been removed








wafer



89















1 Air

2 Humans

3 Facility

4 Water

5 Process chemicals

6 Process gases




89

1 Air





2 Humans


cleanroom








fab cleanroom



89

Air Filtering







68 plusmn 05deg





















89








equipment



the cleanroom air








89

Silicon substrate


Silicon substrate

encapsulation

Metal

Insulator

Active layers

polysilicon








89







performance





89






98




-



(SGS)


999999999










89



Amorphous Structure



89















89




silicon






ingot




89










89










End Removal



ingot

Diameter Grinding




in wafer fabs



89









process




the wafer



the wafer







89














89










integrated circuits



moderate currents




89




are





growth









89



at low temperature




surface
















89



Physical dimensions

Flatness

Microroughness

Oxygen content

Crystal defects

Particles

Bulk resistivity






wafer deformation

Flatness




across the wafer


008 to 012microm



89

Microroughness



nanometers





Oxygen Content









than 1000

Particles



fabrication









89

Bulk Resistivity









ingot


have been removed








wafer



89















1 Air

2 Humans

3 Facility

4 Water

5 Process chemicals

6 Process gases




89

1 Air





2 Humans


cleanroom








fab cleanroom



89

Air Filtering







68 plusmn 05deg





















89








equipment



the cleanroom air








89







performance





89






98




-



(SGS)


999999999










89



Amorphous Structure



89















89




silicon






ingot




89










89










End Removal



ingot

Diameter Grinding




in wafer fabs



89









process




the wafer



the wafer







89














89










integrated circuits



moderate currents




89




are





growth









89



at low temperature




surface
















89



Physical dimensions

Flatness

Microroughness

Oxygen content

Crystal defects

Particles

Bulk resistivity






wafer deformation

Flatness




across the wafer


008 to 012microm



89

Microroughness



nanometers





Oxygen Content









than 1000

Particles



fabrication









89

Bulk Resistivity









ingot


have been removed








wafer



89















1 Air

2 Humans

3 Facility

4 Water

5 Process chemicals

6 Process gases




89

1 Air





2 Humans


cleanroom








fab cleanroom



89

Air Filtering







68 plusmn 05deg





















89








equipment



the cleanroom air








89






98




-



(SGS)


999999999










89



Amorphous Structure



89















89




silicon






ingot




89










89










End Removal



ingot

Diameter Grinding




in wafer fabs



89









process




the wafer



the wafer







89














89










integrated circuits



moderate currents




89




are





growth









89



at low temperature




surface
















89



Physical dimensions

Flatness

Microroughness

Oxygen content

Crystal defects

Particles

Bulk resistivity






wafer deformation

Flatness




across the wafer


008 to 012microm



89

Microroughness



nanometers





Oxygen Content









than 1000

Particles



fabrication









89

Bulk Resistivity









ingot


have been removed








wafer



89















1 Air

2 Humans

3 Facility

4 Water

5 Process chemicals

6 Process gases




89

1 Air





2 Humans


cleanroom








fab cleanroom



89

Air Filtering







68 plusmn 05deg





















89








equipment



the cleanroom air








89



Amorphous Structure



89















89




silicon






ingot




89










89










End Removal



ingot

Diameter Grinding




in wafer fabs



89









process




the wafer



the wafer







89














89










integrated circuits



moderate currents




89




are





growth









89



at low temperature




surface
















89



Physical dimensions

Flatness

Microroughness

Oxygen content

Crystal defects

Particles

Bulk resistivity






wafer deformation

Flatness




across the wafer


008 to 012microm



89

Microroughness



nanometers





Oxygen Content









than 1000

Particles



fabrication









89

Bulk Resistivity









ingot


have been removed








wafer



89















1 Air

2 Humans

3 Facility

4 Water

5 Process chemicals

6 Process gases




89

1 Air





2 Humans


cleanroom








fab cleanroom



89

Air Filtering







68 plusmn 05deg





















89








equipment



the cleanroom air








89















89




silicon






ingot




89










89










End Removal



ingot

Diameter Grinding




in wafer fabs



89









process




the wafer



the wafer







89














89










integrated circuits



moderate currents




89




are





growth









89



at low temperature




surface
















89



Physical dimensions

Flatness

Microroughness

Oxygen content

Crystal defects

Particles

Bulk resistivity






wafer deformation

Flatness




across the wafer


008 to 012microm



89

Microroughness



nanometers





Oxygen Content









than 1000

Particles



fabrication









89

Bulk Resistivity









ingot


have been removed








wafer



89















1 Air

2 Humans

3 Facility

4 Water

5 Process chemicals

6 Process gases




89

1 Air





2 Humans


cleanroom








fab cleanroom



89

Air Filtering







68 plusmn 05deg





















89








equipment



the cleanroom air








89




silicon






ingot




89










89










End Removal



ingot

Diameter Grinding




in wafer fabs



89









process




the wafer



the wafer







89














89










integrated circuits



moderate currents




89




are





growth









89



at low temperature




surface
















89



Physical dimensions

Flatness

Microroughness

Oxygen content

Crystal defects

Particles

Bulk resistivity






wafer deformation

Flatness




across the wafer


008 to 012microm



89

Microroughness



nanometers





Oxygen Content









than 1000

Particles



fabrication









89

Bulk Resistivity









ingot


have been removed








wafer



89















1 Air

2 Humans

3 Facility

4 Water

5 Process chemicals

6 Process gases




89

1 Air





2 Humans


cleanroom








fab cleanroom



89

Air Filtering







68 plusmn 05deg





















89








equipment



the cleanroom air








89










89










End Removal



ingot

Diameter Grinding




in wafer fabs



89









process




the wafer



the wafer







89














89










integrated circuits



moderate currents




89




are





growth









89



at low temperature




surface
















89



Physical dimensions

Flatness

Microroughness

Oxygen content

Crystal defects

Particles

Bulk resistivity






wafer deformation

Flatness




across the wafer


008 to 012microm



89

Microroughness



nanometers





Oxygen Content









than 1000

Particles



fabrication









89

Bulk Resistivity









ingot


have been removed








wafer



89















1 Air

2 Humans

3 Facility

4 Water

5 Process chemicals

6 Process gases




89

1 Air





2 Humans


cleanroom








fab cleanroom



89

Air Filtering







68 plusmn 05deg





















89








equipment



the cleanroom air








89










End Removal



ingot

Diameter Grinding




in wafer fabs



89









process




the wafer



the wafer







89














89










integrated circuits



moderate currents




89




are





growth









89



at low temperature




surface
















89



Physical dimensions

Flatness

Microroughness

Oxygen content

Crystal defects

Particles

Bulk resistivity






wafer deformation

Flatness




across the wafer


008 to 012microm



89

Microroughness



nanometers





Oxygen Content









than 1000

Particles



fabrication









89

Bulk Resistivity









ingot


have been removed








wafer



89















1 Air

2 Humans

3 Facility

4 Water

5 Process chemicals

6 Process gases




89

1 Air





2 Humans


cleanroom








fab cleanroom



89

Air Filtering







68 plusmn 05deg





















89








equipment



the cleanroom air








89









process




the wafer



the wafer







89














89










integrated circuits



moderate currents




89




are





growth









89



at low temperature




surface
















89



Physical dimensions

Flatness

Microroughness

Oxygen content

Crystal defects

Particles

Bulk resistivity






wafer deformation

Flatness




across the wafer


008 to 012microm



89

Microroughness



nanometers





Oxygen Content









than 1000

Particles



fabrication









89

Bulk Resistivity









ingot


have been removed








wafer



89















1 Air

2 Humans

3 Facility

4 Water

5 Process chemicals

6 Process gases




89

1 Air





2 Humans


cleanroom








fab cleanroom



89

Air Filtering







68 plusmn 05deg





















89








equipment



the cleanroom air








89














89










integrated circuits



moderate currents




89




are





growth









89



at low temperature




surface
















89



Physical dimensions

Flatness

Microroughness

Oxygen content

Crystal defects

Particles

Bulk resistivity






wafer deformation

Flatness




across the wafer


008 to 012microm



89

Microroughness



nanometers





Oxygen Content









than 1000

Particles



fabrication









89

Bulk Resistivity









ingot


have been removed








wafer



89















1 Air

2 Humans

3 Facility

4 Water

5 Process chemicals

6 Process gases




89

1 Air





2 Humans


cleanroom








fab cleanroom



89

Air Filtering







68 plusmn 05deg





















89








equipment



the cleanroom air








89










integrated circuits



moderate currents




89




are





growth









89



at low temperature




surface
















89



Physical dimensions

Flatness

Microroughness

Oxygen content

Crystal defects

Particles

Bulk resistivity






wafer deformation

Flatness




across the wafer


008 to 012microm



89

Microroughness



nanometers





Oxygen Content









than 1000

Particles



fabrication









89

Bulk Resistivity









ingot


have been removed








wafer



89















1 Air

2 Humans

3 Facility

4 Water

5 Process chemicals

6 Process gases




89

1 Air





2 Humans


cleanroom








fab cleanroom



89

Air Filtering







68 plusmn 05deg





















89








equipment



the cleanroom air








89




are





growth









89



at low temperature




surface
















89



Physical dimensions

Flatness

Microroughness

Oxygen content

Crystal defects

Particles

Bulk resistivity






wafer deformation

Flatness




across the wafer


008 to 012microm



89

Microroughness



nanometers





Oxygen Content









than 1000

Particles



fabrication









89

Bulk Resistivity









ingot


have been removed








wafer



89















1 Air

2 Humans

3 Facility

4 Water

5 Process chemicals

6 Process gases




89

1 Air





2 Humans


cleanroom








fab cleanroom



89

Air Filtering







68 plusmn 05deg





















89








equipment



the cleanroom air








89



at low temperature




surface
















89



Physical dimensions

Flatness

Microroughness

Oxygen content

Crystal defects

Particles

Bulk resistivity






wafer deformation

Flatness




across the wafer


008 to 012microm



89

Microroughness



nanometers





Oxygen Content









than 1000

Particles



fabrication









89

Bulk Resistivity









ingot


have been removed








wafer



89















1 Air

2 Humans

3 Facility

4 Water

5 Process chemicals

6 Process gases




89

1 Air





2 Humans


cleanroom








fab cleanroom



89

Air Filtering







68 plusmn 05deg





















89








equipment



the cleanroom air








89



Physical dimensions

Flatness

Microroughness

Oxygen content

Crystal defects

Particles

Bulk resistivity






wafer deformation

Flatness




across the wafer


008 to 012microm



89

Microroughness



nanometers





Oxygen Content









than 1000

Particles



fabrication









89

Bulk Resistivity









ingot


have been removed








wafer



89















1 Air

2 Humans

3 Facility

4 Water

5 Process chemicals

6 Process gases




89

1 Air





2 Humans


cleanroom








fab cleanroom



89

Air Filtering







68 plusmn 05deg





















89








equipment



the cleanroom air








89

Microroughness



nanometers





Oxygen Content









than 1000

Particles



fabrication









89

Bulk Resistivity









ingot


have been removed








wafer



89















1 Air

2 Humans

3 Facility

4 Water

5 Process chemicals

6 Process gases




89

1 Air





2 Humans


cleanroom








fab cleanroom



89

Air Filtering







68 plusmn 05deg





















89








equipment



the cleanroom air








89

Bulk Resistivity









ingot


have been removed








wafer



89















1 Air

2 Humans

3 Facility

4 Water

5 Process chemicals

6 Process gases




89

1 Air





2 Humans


cleanroom








fab cleanroom



89

Air Filtering







68 plusmn 05deg





















89








equipment



the cleanroom air








89















1 Air

2 Humans

3 Facility

4 Water

5 Process chemicals

6 Process gases




89

1 Air





2 Humans


cleanroom








fab cleanroom



89

Air Filtering







68 plusmn 05deg





















89








equipment



the cleanroom air








89

1 Air





2 Humans


cleanroom








fab cleanroom



89

Air Filtering







68 plusmn 05deg





















89








equipment



the cleanroom air








89

Air Filtering







68 plusmn 05deg





















89








equipment



the cleanroom air








89








equipment



the cleanroom air






ee503 topic 2 hoo

Documents