NCCAVS Plasma Applications Group MeetingNCCAVS Plasma Applications Group Meeting

EtchTemp Silicon Etch (ET-SE)

Giampietro Bieli: Application Manager

SensArray Division

Executive Summary

� EtchTemp Silicon Etch (ET-SE) targets Poly/STI Etch application

� ET-SE hasY2O3 deposited on top of the Si cover of EtchTemp

� Metal contamination levels are similar to regular EtchTemp (silicon cover)

� Prototype testing in Poly Etch (HBr Chemistry)

� Etch rate of Y2O3 film is minimal to none

� Temperature profile during Poly Etch

11/23/2011 confidential

� Temperature profile during Poly Etch

� Delta temperature between ET-SE Prototype and ET

� No Significant Delta Temp between ET-SE and standard ET

� Temperature profile in continuous Plasma ON condition

� ET-SE shows stable temperature up to 10mins Plasma On

� Prototype testing in Poly Etch (SF6 Chemistry)

� Etch rate of Y2O3 film is minimal to none

EtchTemp-SEPlasma ON Temperature Monitoring of Silicon Etch Processes

� Flat, wireless wafer for in-situ silicon etch

chamber & process temperature monitoring

� Enhancements over silicon etch alternatives

(special coating, wider operating range,

improved S:N, greater lifetime, & lower profile)

� Temperature monitoring with silicon etch

chemistry & plasma ON in key use cases:

Accuracy: +/- 0.2C, Precision: 0.25C, Range: 15-130C

Si top cover

Y2O3 coating

65 sensors,

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EtchTemp-SE

chemistry & plasma ON in key use cases:

� Qualify new etch chambers

� Match etch chambers

� Post-PM chamber verification

� Electrostatic chuck qualification

Enabling Plasma ON Wafer Temperature Monitoring of Silicon Etch Process

Si substrate

65 sensors,

electronics,

shielding,

battery

Use case: Plasma ON details

Accuracy: +/- 0.2C, Precision: 0.25C, Range: 15-130C

Si top cover

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Plasma ON Differences ET VS

ET-SE

Si substrate

65 sensors,

electronics,

shielding,

battery

EtchTemp

Key Spec Comparison

EtchTemp vs. EtchTemp-SE

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No Significant Delta Temp Between ET-SE (Y2O3) and Std. ET Poly Etch

59.73 59.7759.75

63.43 63.71

63.53

57

58

59

60

61

62

63

64

65

Std Silicon cover Vs Y2O3 cover

MEAN

Plasma OFF Mean Plasma ON Mean

Std Silicon cover Vs Y2O3 cover

11/23/2011

Etchtemp with standard silicon cover vs Etchtemp with Yttrium coating

Test to verify that Y2O3 will not affect temperature reading

57

Std ET 1 Std ET 2 Y203

1.67 1.68 1.5

3.8

2.73.5

0

0.5

1

1.5

2

2.5

3

3.5

4

Std ET 1 Std ET 2 Y203

Std Silicon cover Vs Y2O3 cover

RANGE

Plasma OFF Plasma ON

EtchTemp Silicon Etch (ET-SE) ValueDeep Trench Etch

1.5

2

2.5

3

T

E

M

P

D

Center of the wafer show

significant temperature

delta if Proxy recipe is

used

Proxy recipe doesn't to

provide the real

temperature response

2011/11/23 confidential

0

0.5

1

1.5

CENTER EDGE

D

E

L

T

A

Temperature delta using Production recipe (HBr/NF3/O2) and Proxy Recipe

(Ar/O2)

temperature response

Use Case

Chamber A Chamber B

ET-SE

0.86

0.88

0.9

0.92

0.94

0.96

0.98

1

1.02

1.04

15.3

15.8

16.3

16.8

17.3

17.8

CENTER EDGE

T

E

M

P

E

R

A

T

U

R

E

Temp Data

Etch Depth

ET-SE identify edge temperature issue correlated to etch depth issue

DTI Logic

CH A

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EtchDepth

Temperature data correlate to Etch Rate data

Higher Etch Rate= Higher Temperature

0.86

0.88

0.9

0.92

0.94

0.96

0.98

1

1.02

1.04

15.3

15.8

16.3

16.8

17.3

17.8

CENTER EDGE

T

E

M

P

E

R

A

T

U

R

E Temp Data

Etch Depth

CH B

CH BCH BCH ACH A--DOWNDOWN

Full wafer Full wafer Full wafer Full wafer

ET-SE identified Yield issue : CH A production Hold for CDU issues STI Etch

10 KLA-Tencor Confidential - Internal Use Only

CH BCH BCH ACH A--DOWNDOWN

Full wafer Mean DELTA:3.98 degree

Edge onlyEdge onlyEdge onlyEdge only

YIELD ISSUE AT THE EDGE SOLVED WITH ESC REPLACEMENT

CH ACH A--DOWNDOWN

CH ACH A--DOWNDOWN

CH BCH B

CH BCH B

High CD Chamber shows High Wafer Temperature

STI Etch

Tool X

Tool Y

CH A CH B

CH C CH D

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Tool Z

CH E CH F

CH A CH B CH C CH D CH E CH F

ET-SE shows CH D has an outlier , this

correlate to High CD

Golden Chamber

Pre PM bad chamber

Post PM bad chamber

High CD Chamber shows High Wafer Temperature

STI Etch

12 KLA-Tencor Confidential - Internal Use Only

Post ESC replacement fixed the edge temperature spread with

between golden ch and down ch

Golden

Chambers

Pre PM Bad

Chambers

Post PM Bad

Chambers

ESC has many hours

ET-SE identify ESC lifetime impact on TemperaturePoly Etch

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Example of ESC plasma ON data collection that was able to identify

chamber differences due to ESC lifetime

Golden Chamber ESC has low hours

Chamber fleet

ET-SEPoly Etch

�Chamber matching

issue within different

fabs.

�Also, demonstrated

process gas trouble

shooting capability with

ET-SE.

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Golden ChamberChamber ADown Chamber

ET-SE.

�This excursion event

led to a 3-week

chamber down time

before temperature

analysis.

Analysis of Edge Sensors Only

Inner

Outer zone

Mid Inner

Mid outer

CH1 CH2

ET-SE Recommended for 4zone ESC Plasma ON Qualification

Poly Etch

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Inner

CH

1 Temperature analysis by ESC zone in order to

study CD/Yield localized issueCH1 CH2

CH1 CH2

CH1 CH2

PM1PM6

ET-SE Identifies Hot Spot that Correlates to CD Excursion

Poly Mask Etch

74

76

78

80

82

PM1

PM2

PM6

CD Excursion

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PM2

66

68

70

72

74

0 50 100 150 200

PM6

Poly. (PM1)

Log. (PM2)

Poly. (PM6)

PM2 shows CD excursion in lower left edge that correlates to hot spot seen on

ET-SE

High

temperature

area correlate

with CD

excursion

Radial Plot

Temperature Variation across Chambers & Shifts Over Time

Cylinder Support Etch

Old Method: 12hours

Etch Test

Wafer

Measure

CD

Post Etch

Process Test

Wafer

Defect

Inspection

ET-SEPM

Temp

OK?

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Chamber baseline confirmed shifts over time

New Procedure: Post PM temperature data collection for chamber monitor and faster

troubleshooting

ET-SE Method: 30mins

OK?

Conclusion

� ET-SE demonstrated temperature monitoring capability with silicon etch

chemistry & plasma ON in key use cases

� ET-SE is used for :

� Chamber Matching

� Troubleshooting

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� Chamber Monitoring

� Temperature DOE for process optimization

� ESC replacement

� Tool Start up

� Post Pm chamber verification

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