mrs thermal

7/25/2019 MRS Thermal

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Carnegie Mellon University Particle Flow & Tribology Laboratory1

Thermal Effects of CMP as a ParticleAugmented Mixed Lubrication Tribosystem

Gagan Srivastava, C !red "iggs ###Mechanical EngineeringCarnegie Mellon $niversity

Particle !lo% & Tribology Laboratory

MRS Spring Meeting 2013

April 2, 2013

San Francisco, California


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Carnegie Mellon University Particle Flow & Tribology Laboratory

Overview

Motivation

Past works

Modeling

Results

Parametric Studies

Conclusion


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Motivation: Impact of Temperature on CMP

Kim et al. (2002)


4/31Carnegie Mellon University Particle Flow & Tribology Laboratory

CMP Thermal Literature

6

Thermal Analyses in CMP

Quantifying Temperature

ModelingHocheng et al. !!

"hite et al. 0#$orucki et al. 0%

&i et al. 0%'h and Seok 0

ExperimentsSugimoto et al. !

Kim et al. 02Hocheng and

Huang 0%

Sam*urno et al. 0+eomans et al. 0,&ee et al. -2

Effect of Temperature on CMP

ModelingHocheng et al. !!'h and Seok 0

ExperimentsKakiredd et al. 0Hocheng et al. !!

/om et al. 0Kim et al. 02

TEHLModeling

Cheng et al. ,Cheng et al. 0-

Kim et al. 0-"ang et al. 0%

Hachi et al. 0Khan et al. 0!



P1M& lite

Objective

7

3o model the thermal changes in the *ad4 wa5er and

the slurr during CMP


6/31Carnegie Mellon University Particle Flow & Tribology Laboratory8

Physical Interactions Captured in the Model

PAML 'lite

6luid Mechanics Contact Mechanics "ear

6ilm thickness

h 7 h(r48)

Hdrodnamic

Pressure* 7 *9h4 :4 ; 7 >(?4 64 /)

Material Removal

RateMRR 7 f(>4@w4A4B)

Particle namics

Dni5orm

Concentration

Si?e distriution

1ctive ParticlesEactive7f (F4 A4 >)

PAML-liteis a wafer scale model

Particle Gndentation

@ 7 f (4 Hw4 *d)


7/31Carnegie Mellon University Particle Flow & Tribology Laboratory9

Physical Interactions Captured in the T!"M#L Model

PAML 'lite

PAML-liteallows fll wafer scale temperatre anal!sis

6luid Mechanics ContactMechanics "ear

6ilm thicknessh 7 h(r48)

Hdrodnamic

Pressure* 7 *9h4 :4 ; 7 >(?4 64 /)

Material Removal

Rate

MRR 7 f(>4@w4A4B)

Particle namics

Dni5orm

Concentration

Si?e distriution

1ctive ParticlesEactive7f (F4 A4 >)

Particle Gndentation@ 7 f (4 Hw4 *d)

3hermal /55ects

Pad4 "a5er4 Slurr

3em*erature

3 7 f(>4)



P#ML $ lite : Model %lowchart

li d l l h



P#ML $ lite : T!"M#L Model %lowchart

Comptenew" #,$,%

&'ili(rim orientation

)#,$,%*, p+r,-, +r,.-

Calclate Acti/e

Particles

Calclate A/erage

ear

Calclate otal ear

&S

SAR

ess #,$,%0

Film t4ic5ness " 4 +#,$,%0-

Find" flid pressre

p+r,-

6F7,6M8,

6M! 9 0

:;

Find" contact stress

+r,.-

Re!nold



3H/RM1& M'/&GEF

Case II Pad and wa5er tem*eratures without slurr

Case III Pad and wa5er tem*eratures with slurr

12


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Case I: &Temperatures 'ithout (lurry) Methodolo*y

+omains: 'afer, Pad

Interactions

Heat generation at asperity tips

Heat dissipation into pad and wafer


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Case I: &Temperatures 'ithout (lurry) eat -eneration

%lash heatin* concept

Frictional heat generation

Heat partition based on bulk temperaturesand thermal properties of the material

#ssumptions

gnored heat generation due to chemicalreactions! plastic deformation or abrasi"e action

#diabatic edges of the solids

$lok%s con&ecture '(emperature at theasperities are e)ual

32

3-


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Case I: &Temperatures 'ithout (lurry) eat +issipation

Conductive heat transfer across the body

ndi"idually sol"ed for both pad and wafer

*oupled by the heat source +asperities,


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Case I: &Temperatures 'ithout (lurry) Temperatures

15ter , sec o5 actual time

Pad 3em*erature "a5er 3em*erature


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Case I: Temperatures in Pad and 'afer

15ter 20 sec o5 actual time

3'' H'3J

afer


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Overview

+omains: 'afer, Pad,(lurry

Interactions

Heat generation at asperity tips

-issipation of generated heat into pad and wafer

./traction of heat through the fluid

Heat generation in the 5luid


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Case II: &Temperatures 'ith (lurry) eat -eneration

%lash heatin* concept

Frictional heat generation

Heat partition based on bulk temperatures

and thermal properties of the material

#ssumptions

gnored heat generation due to chemical

reactions! plastic deformation or abrasi"e action

#diabatic edges of the solids

$lok%s con&ecture '(emperature at the

asperities are e)ual

32

3-


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Thermal Effects of CMP as a ParticleAugmented Mixed Lubrication Tribosystem

Gagan Srivastava, C !red "iggs ###Mechanical Engineering

Carnegie Mellon $niversityParticle !lo% & Tribology Laboratory

MRS Spring Meeting 2013

April 2, 2013

San Francisco, California


19/31


Case II: &Temperatures 'ith (lurry) eat +issipation

Conductive heat transfer across the body

ndi"idually sol"ed for both pad and wafer

*oupled by the heat source +asperities,

and sourcesink +fluid,

- qconv

- qconv


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Case II: &Temperatures 'ith (lurry) eat !.traction

Convective heat transfer from the solids to the fluid

(woway coupling at the solidfluidinterface

3olid ' Fluid +(emperature,

Fluid ' 3olid +Heat flu/,

6&DG

P1

"16/R

=K(5luL)

3*

ad

3w

a5er

Case II Temperature /ariation in the Pad


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Case II: Temperature /ariation in the Pad

Case II: Temperature /ariation in 'afer and (lurry


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24

Case II: Temperature /ariation in 'afer and (lurry


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Results

25


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Material "emoval: Model /alidation

Chan*e in avera*e temperature rise, with process parameters

26

0 -0000 20000 #0000 %0000 0000 ,0000 M0000 0000

0

0.0-

0.02

0.0#

0.0%

0.0

0.0,

0.0M

0.0

0.0!

3em*erature Rise vs /nerg Gn*ut

(Gn terms o5 a**lied *ressure and *laten s*eed)

PHB (gNcm2 H mNmin)

Gncrea

sein3em*erature(de

gC)

Kim et al. (2002)


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Parametric (tudies

eat *eneration properties

27

0 0.002 0.00% 0.00, 0.00 0.0- 0.0-2

0

0.00-

0.002

0.00#

0.00%

0.00

0.00,

0.00

0.00

0

-0

-

20

2

#0

#

%0

%

MRR and 3em*erature Rise vs Biscosit o5 the Slurr

MRR

delta3

Biscosit (PaOs)

3em*eratureR

ise(degC)

MRR

(nmNmin)


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Parametric (tudies

Conduction 0 Convection Properties

28

0.- - -0 -00

0

0.0-

0.02

0.0#

0.0%

0.0

0.0,

3em*erature Rise 5or i55erent 6luid Conductivities

3hermal Conductivit o5 6luid ("NmOK)

Kwa5erK*ad


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Conclusion

# new approach to model thermal effects durin* CMP hasbeen presented

The approach was able to justify the presence of slurry as a heat

e.traction medium

The model predictions match well with the e.perimental observations

The model showed hi*her avera*e temperatures for hi*her

values of viscosities

Predictive capabilities of the model will allow us to en*ineer

consumables better

29


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#c1nowled*ements

Philip and Marsha +owd (eed %und

Cabot Microelectronics &In kind contributions)

0


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D/S3G'ES Q


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1PP/EG


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