the effect of conditioner design on pad texture...pad texture morgan advanced ceramics ... final...

Morgan Technical CeramicsInnovation in Innovation in

Materials TechnologyMaterials Technology

The Effect of Conditioner Design on Pad Texture

Morgan Advanced CeramicsDiamonex® Products Division

David SlutzJuly 17, 2008

Innovation in Innovation in Materials TechnologyMaterials TechnologyMorgan Technical Ceramics

Slide 2

Phoenix® CMP Pad Conditioner

Fine Medium Coarse

CVD Diamond Coated Diamond Grit


Slide 3

Phoenix® edge CMP Pad Conditioner

Design A

Design B

Design C



Pad Texture Results


Slide 5

Phoenix Medium Grit Conditioner- Interferometry

Inner Middle OuterSurface Height (microns)

403020100

-10

-20

-30

-40 Numerous large asperities, source of wafer defects.


Slide 6

Pad Texture (Medium Grit)

0

2

4

6

8

10

12

Phoenix(Medium Grit)

Sinusoidal SweepConditioner

Surf

ace

Text

ure

(λ)

Inner Diameter Middle Outer Diameter


Slide 7

Phoenix Fine Grit - Interferometry Line 2

Inner Middle Outer

Surface Height (microns)

403020100

-10

-20

-30

-40


Slide 8

Pad Texture

0

2

4

6

8

10

12


Sinusoidal Sweep

Phoenix (Fine Grit)

Sinusoidal SweepConditioner

Surf

ace

Text

ure

(λ)



Slide 9

2x2 mm image

Groove

Groove

Phoenix edge pad Conditioner - Interferometry

Inner(2.75”) Middle(5.125”) Outer(7.50”)

Groove

Groove

Groove

Groove

Fewer large asperities, more uniform surface. Increased contact area, reduced defects.


Slide 10

Pad Surface Texture Comparison

0

2

4

6

8

10

12


Sinusoidal Sweep

Phoenix (Fine Grit)

Sinusoidal Sweep

Phoenix edge B Phoenix edge A

Conditioner

Surf

ace

Text

ure

(λ)



Slide 11

Interferometry DataS

urfa

ce H

eigh

t (m

icro

ns)

40

30

20

10

0

-10

-20

-30

-40

Phoenix Phoenix PhoenixMedium Fine edge



Pad Texture Result

for Copper Process


Slide 13

– Wafer• 200-mm blanket copper wafer

– Pad• IC1020 M groove

– Slurry• 200 ml of Fujimi PL-7103 slurry + 800

ml of DI H2O + 33 grams of 30% ultra pure H2O2

– Rinse• DI H2O flow rate 2,000 ml/min

for 30 seconds.

Experiment Conditions

– Pad Conditioning• Morgan Diamond Discs

• Phoenix Fine grit• Phoenix Medium grit• Phoenix Coarse grit• Phoenix edge Design C (2 runs)

• In-situ pad conditioning = 6 lbf

• Tweaked optimized sweep• 2nd Phoenix edge- sinusoidal sweep

– Wafer Polishing • Polishing pressure = 2 PSI• Platen sliding velocity = 42 RPM• Polishing time = 60 seconds


Slide 14

Composite Topography Images

Phoenix Coarse Grit

Phoenix Medium Grit

Phoenix Fine Grit

Phoenix edge-Run 1

Phoenix edge-Run 2


Slide 15

Phoenix MediumPhoenix Coarse Phoenix Fine

Phoenix edge-Run 1 Phoenix edge- Run 2

Summit Height Distributions


Slide 16

15

16

17

18

19

20

21

22

PhoenixCoarse Grit

PhoenixMedium Grit

PhoenixFine Grit

Phoenix edgeRun 1

Phoenix edgeRun 2

Mea

n As

perit

y He

ight

(µ)

0%

10%

20%

30%

40%

50%

60%

70%

% A

sper

ity H

eigh

t >20

µ

Mean Asperity Height (µ) % Asperity Height >20 µ

Asperity Height (Mean & >20um)

Edge CuttingPoint Cutting


Slide 17

Surface Height Probability Density Functions

0.00001

0.0001

0.001

0.01

0.1

1

-50 -40 -30 -20 -10 0 10 20 30

Surface Height (um)

Surf

ace

Hie

ght P

roba

bilit

y De

nsity

(1/u

m)

Phoenix Coarse Grit

Phoenix Medium Grit

Phoenix Fine Grit

Phoenix edge-Run 1

Phoenix edge-Run 2


Slide 18

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

PhoenixCoarse Grit

PhoenixMedium Grit

PhoenixFine Grit

Phoenix edgeRun 1

Phoenix edgeRun 2

% A

perit

y H

eigh

t >20

µ

4

5

6

7

8

9

10

Pad

Text

ure

(Å)

% Asperity Height >20 µ Pad Texture (Å)

Pad Texture and % Asperity Heights >20µ


Decreasing number of large asperitiesi.e. smoother pad surface texturewith decreasing diamond size


Slide 19

Phoenix edge-Run 1

Phoenix Fine

Sharp

Phoenix MediumPhoenix Coarse

Phoenix edge- Run 2

Summit Sharpness


Slide 20

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

PhoenixCoarse Grit

PhoenixMedium Grit

PhoenixFine Grit

Phoenix edgeRun 1

Phoenix edgeRun 2

Mea

n Su

mm

it Sh

arpn

ess

(µ-1

)

0%

5%

10%

15%

20%

25%

30%

35%

40%

45%

% S

umm

it Sh

arpn

ess

>1 µ

-1

Mean Aperity Sharpness (µ-1) % Sharp Asperities >1 µ-1

Summit Sharpness (Mean & Sharp)


Decreasing asperity sharpness with decreasing diamond size

Edge cutting is a different mechanism


Slide 21

Phoenix Coarse Grit- Image 8

Contour atz=14.0 µm

50 µm


Slide 22

Phoenix Coarse Grit- Image 8 at 2 psi

50 µm

Contact Area Shape is mostly round


Slide 23

Phoenix Medium Grit- Image 5 at 2 psi

50 µm

Contact Area shapes are round and elongated


Slide 24

Phoenix Fine Grit- Image 3 at 2 psi

50 µm

Contact Area shapes are mostly elongated


Slide 25

Phoenix edge- Image 12 at 2 psi

50 µm

Contact area shapes are elongated and curled


Slide 26

Composite Contact Area Images

Sliding Direction

Phoenix Coarse Grit

Phoenix Medium Grit

Phoenix Fine Grit

Phoenix edge-Run 1

Phoenix edge-Run 2


Slide 27

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

Competitors PhoenixCoarse Grit

PhoenixMedium Grit

PhoenixFine Grit

Phoenix edgeRun 1

Phoenix edgeRun 2

Mea

n C

onta

ct A

rea

(%)

0

100

200

300

400

500

600

700

800

900

Mea

n C

onta

ct D

ensi

ty (#

/mm

2 )

Mean Contact Area (%) Mean Contact Density (#/mm2)

Contact Area decreases with decreasing diamond size

Contact Area Percentage & Point Density

Edge CuttingCVD Diamond Point CuttingSingle Crystal Point

Cutting

The CVD Diamond on the single crystal diamond produces a pad surface with much higher contact area than bare diamond


Slide 28

Mean Contact Pressure

0

2000

4000

6000

8000

10000

12000

14000

16000

18000

Competitors PhoenixCoarse Grit

PhoenixMedium Grit

PhoenixFine Grit

Phoenix edgeRun 1

Phoenix edgeRun 2

Mea

n C

onta

ct P

ress

ure

(psi

)

Sing

le C

ryst

al P

oint

Cut

ting

Edge CuttingCVD Diamond Point Cutting


Slide 29

Contact Area Size Distribution

Phoenix edge- Run 1 Phoenix edge- Run 2

Phoenix FinePhoenix MediumPhoenix Coarse


Slide 30

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

PhoenixCoarse Grit

PhoenixMedium Grit

PhoenixFine Grit

Phoenix edgeRun 1

Phoenix edgeRun 2

Mea

n C

onta

ct A

rea

Size

(µ2 )

0.0%

0.5%

1.0%

1.5%

2.0%

2.5%

3.0%

3.5%

% C

onta

ct A

rea

Size

>10

0 µ2

Mean Contact Area Size (µ2) % Contact Area >100 µ2

Contact Area Size (Mean & Large)


Size of the contact areas decreases with decreasing diamond size in particular the number of largest areas



Copper Process Data Results


Slide 32

Copper Removal Rate & Non-Uniformity

0

1000

2000

3000

4000

5000

6000

PhoenixCoarse Grit

PhoenixMedium Grit

PhoenixFine Grit

Phoenix edgeRun 1

Phoenix edgeRun 2

Mea

n C

oppe

r Rem

oval

Rat

e (Å

/min

)

0%

10%

20%

30%

40%

50%

60%

Mea

n Un

iform

ity (%

)

Mean Copper Removal Rate Mean Uniformity (%)

~50% Increase In Copper Removal Rate



Slide 33

2000

2500

3000

3500

4000

4500

5000

0.42 0.44 0.46 0.48 0.50 0.52 0.54 0.56 0.58 0.60

Coefficient of Friction

Cop

per R

emov

al R

ate

(Å/m

in)

PhoenixCoarse Grit

PhoenixMedium Grit

PhoenixFine Grit

Phoenix edgeRun 1

Phoenix edgeRun 2

Copper Removal Rate vs. COF

Point Cutting

Edge Cutting

~42% Increase In Copper Removal Rate @ Same COF


Slide 34

2000

2500

3000

3500

4000

4500

5000

25.6 25.8 26.0 26.2 26.4 26.6 26.8 27.0 27.2 27.4

Pad Temperature (ºC)

Cop

per R

emov

al R

ate

(Å/m

in)

PhoenixCoarse Grit

PhoenixMedium Grit

PhoenixFine Grit

Phoenix edgeRun 1

Phoenix edgeRun 2

~42% Increase In Copper Removal Rate @ Same Temperature

Copper Removal Rate vs. Pad Temperature

Point Cutting

Edge Cutting


Slide 35

Pad Cut Rates

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

PhoenixCoarse Grit

PhoenixMedium Grit

PhoenixFine Grit

Phoenix edgeRun 1

Phoenix edgeRun 2

Nor

mal

ized

Pad

Cut

Rat

e


Decreasing Pad cut rate with decreasing diamond size


Slide 36

Summary-Edge Cutting verses Point Cutting

Pad Texture Edge cutting produces a smoother pad texture with fewer large asperitiesEdge cutting produces asperity shapes with a sharpness in the mid range of point cutting. However, for point cutting the number of sharp asperities decreases with diamond size. Edge cutting produces smaller elongated curled contact area shapes as opposed to larger round contact regions for point cutting.Edge cutting produces less contact area, fewer number of contacts, and fewer large contact regions.

Copper ProcessEdge cutting resulted in ~50% increase in copper removal rate over point cutting.Edge cutting resulted in comparable non-uniformityEdge cutting resulted in vastly reduced pad cut rate over point cutting


Slide 37

Final Thoughts

What causes the increase in copper removal rate?COF & pad temperature can not explain the increase in MRR for edge cuttingPad surface features and interaction with wafer

•No one pad feature shows a direct relationship to MRR.•Combination of pad features might explain the increase in MRR

Slurry flow and mixing due to the geometric design of the spiralconditioner is a strong possibility.

Future Work: Continue work to find any correlation between Pad texture and MRRInvestigate the effect of conditioner geometry on MRR Marathon study to determine Phoenix edge conditioner life, stability of process, and defectivity


Slide 38

Acknowledgements



Thank You

the effect of conditioner design on pad texture...pad texture morgan advanced ceramics ... final...

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