Front-end, Back-end and Substrate Slurries: Key Process...

copyright : Asahi Glass Co.,Ltd.

Your Global Partner in Material Solutions™

Front-end, Back-end and Substrate Slurries:

Key Process Data and Advantages


Current Products

• Ceria Slurry

– STI/RMG process (used for 22nm HVM)

– Poly Si CMP: high rate and selective to oxide and

SiN

– Poly Stop – High TEOS/Poly selectivity

– TSV – Backside: Tunable Cu, TEOS rate

• Cu Slurry

– TSV: Frontside: high Cu rate, Cu/Ta, Ti ratio

– Cu : High planarization on soft pad

• Barrier: Customized for integration

• Sapphire: good Ra, low cost

• SiC: good Ra


Device Integration and Polishing applications

Logic application TSV application

Cu / Barrier CMP APLANADOR series

PMD CMP CES series

STI CMP CES seriesW

Cu

P-well N-well

Substrate

STI

Cu

Cu

Poly-Si

Si

Poly-Si CMP CES series

High Cu rate CMPAPLANADOR series

Cu SiBare-Si CMP CES series

Flash application DRAM applicationCu / Barrier CMP

APLANADOR series

ILD CMP CES series

STI & RMG CMP CES series

Poly-Si CMP CES series

Capa-citor

Cu

W

Substrate

Cu

W

STI

Substrate

Poly-Si

STI


CES-330F New

defe

ct c

ount

The CES-350 abrasive show 1/3 of the defectivity for CES-330 abrasive.

Comparison of defect count as a function of ceria particle size

CES-350F


Step Height Reduction and Overfill Removal:

• CES-333-2.5 demonstrated auto-stop properties.

• Thick overfill cleared by dilute slurry polishing.

• High selectivity to SiN

0

1000

2000

3000

4000

5000

6000

7000

8000

0 30 60 90 120 150 180 210

Polishing time (sec)

Act

ive

HD

P T

hic

kn

ess

(A)

500um L/S50um L/S30% dens70% dens.

Auto stop Diluted slurry

5000

5500

6000

6500

7000

7500

0 30 60 90 120 150 180 210

Polishing time (sec)

Fie

ld H

DP

Thi

ckne

ss (

A)

500um L/S50um L/S30% dens.70% dens.

Auto stop Diluted slurry

CES 333F series type slurry for STI and RMG

copyright : Asahi Glass Co.,Ltd.Page 6

pressure

Removal

rate

pressure

Removal

rate

Auto stop polishing

Polishing pressure

Low dishing polishing

Polishing pressure

Threshold > polishing pressure Threshold < polishing pressure

Additive chemistry engineering for improved planarization: Concept of higher planarity polishing slurry

Higher planarity -smaller dishing (range)-smaller SiN loss (range)

Removal rate would be lower,

when step height cleared.

Removal rate would be lower,

when dishing occurred.


pressure

Rem

ova

l

rate

Polishing pressure

CES-333

CES-336

New additives protect trench oxide at low down force area.

Removal rate ratio(High/low pressure) is higher with new additive.

Concept of new additive for higher planarity

In case of Oxide clearing polish


2000

2500

3000

3500

4000

4500

5000

5500

0 50 100 150 200

tre

nch

oxi

de

th

ickn

ess

[A]

polish time[s]

100um/100um

50um/50um

30um/70um

70um/30um

2000

2500

3000

3500

4000

4500

5000

5500

0 50 100 150 200

tre

nch

oxi

de

th

ickn

ess

[A]

polish time[s]

100um/100um

50um/50um

30um/70um

70um/30um

2000

2500

3000

3500

4000

4500

5000

5500

0 50 100 150 200

tre

nch

oxi

de

th

ick

ne

ss[A

]

polish time[s]

100um/100um

50um/50um

30um/70um

70um/30um

CES-336F series for high planarity and over-polish Window

1:3dil CES-333F-2.5 1:3dil CES-336F-2.4/3.6

1:3dil CES-356F-2.4/3.6

CES-330 F + ADD-106 = CES-336F slurry

Improved Dishing and over-polish margin.

Results of patterned wafer polishing (trench oxide)


0

200

400

600

800

1000

1200

0 10 20 30

Dis

hin

g[A

]

over polish[%]

100um/100um

50um/50um

30um/70um

70um/30um

0

200

400

600

800

1000

1200

0 10 20 30

Dis

hin

g[A

]

over polish[%]

100um/100um

50um/50um

30um/70um

70um/30um

0

200

400

600

800

1000

1200

0 10 20 30

Dis

hin

g[A

]

over polish[%]

100um/100um

50um/50um

30um/70um

70um/30um

Dishing as a function of over-polish

1:3dil CES-333F-2.5 1:3dil CES-336F-2.4/3.6

1:3dil CES-356F-2.4/3.6

/Slurry with ADD-106 showed wider over

polish margin against dishing.


0

250

500

750

1000

1250

1500

500u

m L

/S

250u

m L

/S

100u

m L

/S

50um

L/S

25um

L/S

10um

L/S 10

%

20%

30%

40%

50%

60%

70%

Ste

p H

eigh

t [A

]

Si l ica slu r ry on ly

AGC cer ia + si l ica

cer ia on ly process

High selective Poly Si slurry: Two step Ceria slurry process for reduced step height

Conventional Ceria slurry polish for planarization

High selective Poly-Si slurry for poly-Si clearing and stop on oxide.


Poly Si stop Slurry with high oxide rate


0

10

20

30

40

50

60

70

80

90

100

0

50

100

150

200

250

300

350

400

450

500

0 200 400 600 800 1000

PE [%

]

Step

Hei

ght [

nm]

Removal Amount [nm]

High Planarization Efficiency on Soft Pad

• CL-1524 has good PE.

Equipment/Consumables

・ Equipment: AMAT Mirra

・ Slurry: CL-1524

・ Polishing Pad: softer pad

・ Conditioner:

・ Wafer: Sematech 854 Pattern

Polishing condition

・ Polishing Time: 30, 50 sec

・ Membrane/R-ring Pressure : 2.0 / 4.0 psi

・ Platen/Head rotation speed: 123 / 117 rpm

・ Slurry flow rate: 200 ml/min

・ Conditioning: Ex-situ 30 sec

Line/Space = 0.18/0.18μm

Isolated = 100μm

Line/Space = 10/10μm

Density = 90%

Step Height

PE

CL-1500 Series Cu slurry: CL-1524

End Point


CL-2100 Series Barrier Slurry: Customization for Integration scheme & Design Concept

• Cu removal rate (R/R) is controlled by H2O2 content.

• TEOS R/R is controlled by abrasive content and size.

• Low-k R/R is controlled by variation of suppresser and quantity.

Str

ong

We

ak

Cu

pro

tectio

n

Cu R

em

ova

l Ra

te

CL-214X SeriesCu/TEOS

non-selective type

M

M

CL-213X SeriesCu high

removal rate typeCL-216X SeriesTEOS/Low-k high

selective type

H

H


CX-1001 Series Front side TSV slurry

• Cu/Ta Selectivity is [email protected], [email protected]

• Cu/Ti Selectivity is [email protected], [email protected]

Removal Rate Removal Profile

0

1

2

3

4

5

6

-100 -80 -60 -40 -20 0 20 40 60 80 100

Ta R

emov

al R

ate

[nm

/min

]

X Position [mm]

2.0psi 4.0psi

Membrane

0

10

20

30

40

50

60

-100 -80 -60 -40 -20 0 20 40 60 80 100

Ti R

emov

al R

ate

[nm

/min

]X Position [mm]

2.0psi 4.0psi

Membrane

0.5 1.8

22.2

50.4

0

10

20

30

40

50

60

0 1 2 3 4

Rem

oval

Rat

e [n

m/m

in]

Membrane [psi]

Cu

Ta

Ti

3228.3 4793.5 Ta

Ti

High Copper Removal Rate and barrier Selectivity


0

0.2

0.4

0.6

0.8

1

1.2

Abrasive0.05%

Abrasive0.25%

Abrasive0.05%

Abrasive0.25%

APS 0.4% APS 0.5%

Rem

oval

Rate

[um

/m

in]

Cu

TEOS

b-Si

Si/Cu Non-selective slurry (High TEOS RR type)

IT M R.R Platen Head Slurry

[psi] [psi] [psi] [rpm] [rpm] [mL/min]

4 4 4.6 127 123 200

Slurry: CES-330 series for Silicon/Copper polish Polisher: AMAT MirraPad: IC-1000/Suba 400 XY-P (A21)Conditioning: Mitsubishi Material MEC-100, ex-situ 9lbfWafer: bare-Si, Cu, Ta, TEOS Polish Time: bare-Si 5min, Cu, TEOS 1min, Ta 10sec

High TEOS rate without changing the rate of Si and Cu

Ceria Based back side TSV slurry:


UD 1900B Sapphire slurry: Low Cost Removal rate

UD1900B on suede pad maintains high removal rate with wide dilution range.

⇒Slurry cost reduction!

⇒Minimal removal rate change due to slurry dilution shift.

Polishing pressure (psi) Rotation speed (rpm)

UD1900B/suede 3.0 60


Sapphire surface roughness & scratch

UD1900B/suede shows very smooth surface and

no scratches on surface.

SEM images after polishing with UD1900B/suede

Sapphire

wafer

Center

Five points

measurementRa=0.10nm

UD1900B/suedeEquipment

SEM

Zygo


Ra=0.09nm

18

UD-1405 SiC substrate polish slurry

SiC: good Ra

Surface observation by AFM

( 3’’ , On-axis , Si )

X=5um,Y=5um

Achieves high planarity ( Ra < 0.1nm )

Front-end, Back-end and Substrate Slurries: Key Process...

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