Investigation of Valve Effects on Wafer Defectivity using an Oxide Slurry

Budge Johl and Hethel Porter“2007 3rd Annual Levitronix CMP

User Conference”Rohm and Haas Electronic Materials

CMP Technologies Phoenix, AZ

Outline

Objective of Study

Experimental Setup

Historical Data

Analytical Results & Discussion

Polishing Results

Summary

Objective

Test New Valve vs. Old Valve Technologies on Oxide Slurry Shear Effects.

Collect Analytical Data to Ascertain any Shifts in Slurry Health.

Polish Wafers and Review Polishing Performance Effects of Valve Technologies.

Acknowledgements:

Parker Hannifin Corp. (Valves)

Levitronix (Pump)

Rohm and Haas (CMPIC Polishing Lab.)

New Valve Technology

OLD TECHNOLOGY

NEW! TECHNOLOGY

Tongue & Groove caused Areas for Slurry to Cake Up and Cause Premature Failure and Leak by

Enhanced Flow CharacteristicsNo Areas for Entrapment or Agglomeration

Slide Courtesy of Parker Hannifin Corp.

Sample Port

MaglevPump

SlurryTank

Valve Actuator

Test Valve

Experimental Setup

PolishingPolishing Tool Used:

Applied Materials Mirra®

Wafer Type:TEOS Blanket Wafers

Slurry:Klebosol™ 1501-50 Oxide Slurry

Pads:IC1010™

Politex™

Suba™

Conditioner:DiaGrid™

Klebosol is a registered trademark of AZ Electronic Materials

IC1010, Suba, and Politex are tradmarks of Rohm and Haas Company or its affiliates,

DiaGrid is a registered trademark of Kinik Co.

Mirra is a Registered Trademark of Applied Materials, Inc.

Historical Large Particle Size ResultsOxide Slurry

Levitronix Pump (Without Valves)

Micron Size (µ)

0 5 10 15 20

Cum

ulat

ive

Cou

nts

> D

iam

eter

0

500

1000

1500

2000

Time 0 HourTime 24 Hour (~3x > Turnovers)

Historical Pump Results without Valves

Oxide RR and Defectivity Response

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

Defect Counts RR

Wafer Results

Nor

mal

ized

Val

ues

STANDARD (0 Hour)

LEVITRONIX (336 Hour)

Analytical Lab Testing

Laboratory Analysis:

Large & Mean Particle Size

Zeta Potential

Conductivity

pH

Viscosity

Density

Total Percent Solids

Large Particle Size Results

Parker Old Valve vs. New ValveTechnologyLevitronix Pump Recirculated Oxide Slurry

Micron Size (µ)

0 1 2 3 4 5

Cum

ulat

ive

Cou

nts

> D

iam

eter

0

200

400

600

800

1000

Old Valve Delta (24 Hour)New Valve Delta (24 Hour)

Delta of LPD

ANOVA Analysis

Data Shows Significant Difference Between Valve Technologies

0

500

1000

1500

2000

2500

Del

ta P

artic

le S

ize

(u)

New Old

Valve Type

Each PairStudent's t0.05

Possible Effects of LPD Shift

Effects of Slurry Shear:

Increase in LPD’s

Decreased Filter Life

Distribution System Cleanliness

Day-tanks

Valves, Pneumatic & Manual

Synergistic Effects with Poor Pumps

May Effect Wafer Defectivity Over Time

May Influence RR & % NU

Filter Life Reduction

0

100

200

300

400

500

600

700

800

900

9:56:07 AM 9:58:59 AM 10:01:54 AM 10:04:49 AM 10:07:44 AM 10:10:39 AM 10:13:34 AM

Time

Flow

(mL/

min

)

0

5

10

15

20

25

30

35

Del

ta P

(psi

)

Flow(L/min)Delta-Pressure(psig)

Filter Life can be Reduced with Increased Slurry and Gels and Agglomerations

Mean Particle Size (nm)

ANOVA Analysis

No Significant Difference between New and Old Valves on Mean Particle Size Distribution

70

72

74

76

78

80

82

84

Mea

n P

artic

le S

ize

(nm

)

New Valve Old Valve

Valve Type

Each PairStudent's t0.05

Mean Particle Size (nm) of New vs. Old Valve

25

45

65

85

105

125

0 5 10 15 20 25

Sampling Time (hr)

MP

S (n

m)

New Valve Old Valve

Zeta Potential (mV)

ANOVA Analysis

No Significant Difference between New and Old Valves on Zeta Potential

-36

-36.2

-36.4

-36.6

-36.8

-37

Zeta

Pot

entia

l (m

V)

New Valve Old Valve

Valve Type

Each PairStudent's t

0.05

Zeta Potential (mV) of New vs. Old Valve

-40.00

-38.00

-36.00

-34.00

-32.00

0 5 10 15 20 25

Sampling Time (hr)

Zeta

Pot

entia

l (m

V)

New Valve Old Valve

Conductivity

ANOVA Analysis

No Significant Difference between New and Old Valves on Conductivity

2900

2950

3000

3050

3100

3150

3200

Con

duct

ivity

(uS

/cm

)

New Valve Old Valve

Valve Type

Each PairStudent's t0.05 Conductivity (uS/cm) of New vs. Old Valve

2000

2500

3000

3500

4000

0 5 10 15 20 25

Sampling Time (hr)

Con

duct

ivity

(uS

/cm

) New Valve Old Valve

pH

ANOVA Analysis

No Significant Difference between New and Old Valves on pH

10.5

10.6

10.7

10.8

10.9

pH

New Valve Old Valve

Valve Type

Each PairStudent's t

0.05pH of New vs. Old Valve

10.5

10.6

10.7

10.8

10.9

0 5 10 15 20 25

Sampling Time (hr)

pH

New Valve Old Valve

Viscosity

ANOVA Analysis

No Significant Difference between New and Old Valves on Viscosity

2

2.1

2.2

2.3

Vis

cosi

ty (c

P)

New Valve Old Valve

Valve Type

Each PairStudent's t

0.05 Viscosity (cP) of New vs. Old Valve

0.00

1.00

2.00

3.00

4.00

5.00

0 5 10 15 20 25

Sampling Time (hr)

Vis

cosi

ty (c

P)

New Valve Old Valve

Density

ANOVA Analysis

No Significant Difference between New and Old Valves on Density

1.19

1.195

1.2

1.205

1.21

1.215

1.22

Den

sity

(g/m

L)

New Valve Old Valve

Valve Type

Each PairStudent's t0.05

Density of New vs. Old Valve

1.200

1.202

1.204

1.206

1.208

1.210

0 5 10 15 20 25

Sampling Time (hr)

Den

sity

(g/m

L)

New Valve Old Valve

Total Percent Solids

No Significant Difference between New and Old Valves on Total Percent Solids

ANOVA Analysis

30.5

30.75

31

31.25

31.5

Tota

l Per

cent

Sol

ids

New Valve Old Valve

Valve Type

Each PairStudent's t0.05 Total Percent Solids of New vs. Old Valve

30

30.5

31

31.5

32

0 5 10 15 20 25

Sampling Time (hr)

Tota

l Per

cent

Sol

ids New Valve Old Valve

ANOVA Analysis of Removal Rate and % NU

% NU

No Significant Difference on RR and %NU

Normalized Removal Rate

0.985

0.995

1.005

1.015

1.025

Nor

mal

ized

RR

Filtered New Valve Unfiltered-Control Old ValveEach PairStudent's t

0.05

1

1.5

2

2.5

3

3.5

4

% N

U

Filtered New Valve Unfiltered-Control Old Valve Each PairStudent's t0.05

Defectivity

Filtered Unfiltered - Control New Valve Old Valve

No Significant Difference on Defect Counts

ANOVA Analysis

0.5

0.75

1

1.25

1.5

Nor

mal

ized

Def

ect C

ount

Filtered New Valve Unfiltered-Control Old Valve Each PairStudent's t

0.05

Summary

Increase in Large Particle Size Distribution was Evident with Old Valve Technology

This Shift can Decrease Filter Lifetimes

Distribution System Cleanliness can be Effected

The Data Shows that Polishing Results Showed No Significant Differences in:

Defectivity

RR

% NU

Summary

Synergistic Response on Wafer Defectivity may be more Evident if:

Old Valve Technologies are Coupled with Shear-causing Distribution Systems

Number of Valves in the Distribution System

Slurry Distribution System Resident Time

Wafer Defectivity may Vary with Specific Slurry Chemistries

THANK YOU FOR YOUR TIME

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