Chuck Cleaning Wafer (CCW) to remove dusts /particles on wafer chuck (Electrostatic, Vacuum,Mechanical) to be cause of machine troubles【Contact】
KYODO INTERNATIONAL INC.
http://www.kyodo-inc.co.jp/
2-10-9 Miyazaki Miyamae-ku, Kawasaki-shi,
Kanagawa-ken, 216-0033 Japan
TEL:+81-44-852-7575 FAX:+81-44-854-1979
email:denshi@kyodo-inc.co.jp

About Chuck Cleaning Wafer（CCW）

A cleaning wafer to remove dusts or particles on waferchucks. A polymer pasted on the surface of a silicon wafer
absorbs dusts or particles when it contacts with the chuck.
Customers can realize the effect of the performance of theCCW by carrying it like as same as production wafers.

CCWPolymersurface

Put the polymer surface of theCCW on the chuck surface
where particles exist

The polymer is absorbed onto the chucksurface by the vacuum absorption effectof the chuck. The polymer has elasticity

Particles stick to thepolymer andremoved

Chuck Cleaning Wafer (CCW) shows
superior effect in the following points
 The number of dummy wafers to be run after chamber cleaning(after PM / trouble occurrence) is greatly reduced.
（e.g. before CCW use : 50pcs ➡ after CCW use : 2-3pcs）
 Photolithography：It solves the problem of hot spot which causes focus defect.

 Etching：It solves the Helium leak problem caused by dust on the chuck.

 Sputtering：It solves the Helium leak problem caused by dust on the chuck.
It also contributes to improvement of thin film uniformity.

 CCW for etching and sputtering process can be recycled more thanonce by using Particle Removal Film (PRF).

As a result, manufacturing loss at downtimeis greatly improved ： Case-1
In Photolithography【Assumption / trial calculation】
・Hot spot occurred 4 times / month for eachequipment
・Set the throughput to 130 wafers / hour・Set the occupancy rate to 80%
・Includes equipment startup time in downtime【Estimate of the amount lost in an hour】
In the case of 300mm：@250,000/Hr
In the case of 200mm：@90,000/Hr（Depreciation, labor costs, utilities, parts for
wet clean, downtime etc. ）【Estimate the number of wafers that were
not processed during that time 】
In the case of 300mm：104 wafersIn the case of 200mm：104 wafers

With CCW operation,
・CCW usage times : 50 times
・Remove 75% of hot spot
【In the case of 300mm】· Cost reduction of ¥ 3,300,000 /batch· Throughput improvement for 3,900
wafers【In the case of 200mm】· Cost reduction of ¥ 3,300,000 /batch· Throughput improvement for 3,900
wafersAs a result, manufacturing loss at downtime
is greatly improved ： Case-2
In Etching【Assumption / trial calculation】
・Helium leak occurred 2 times / month for eachequipment
・Necessity for outsourcing to replacement partsand external cleaning occurs
・Set the throughput to 37 wafers / hour・Set the occupancy rate to 80%
・Includes equipment startup time in downtime【Calculate the amount of loss that will belost in 8 hours downtime 】
In the case of 300mm：¥750,000（Depreciation, labor costs, utilities, parts forwet clean, downtime etc. ）【Estimate the number of wafers that were
not processed during that time 】
In the case of 300mm：240 wafers

With CCW operation,
・CCW usage times : 20 times(100 times possible with PRF)
· 75% reduction in Helium
leak generation【In the case of 300mm】· Cost reduction of ¥ 11,100,000 /batch· Throughput improvement for 3,600wafers➡You can extend the interval of wetcleaningAs a result, manufacturing loss at downtime
is greatly improved ： Case-3
In Sputtering【Assumption / trial calculation 】
・Helium leak occurred 2 times / month for eachequipment
・Necessity for outsourcing to replacement partsand external cleaning occurs
・Set the throughput to 37 wafers / hour・Set the occupancy rate to 80%
・Includes equipment startup time in downtime【Calculate the amount of loss that will belost in 8 hours downtime 】
In the case of 300mm：¥1,100,000（Depreciation, labor costs, utilities, parts for
wet clean, downtime etc. ）【Estimate the number of wafers that were
not processed during that time 】
In the case of300mm：224 wafers

With CCW operation,
・CCW usage times : 20 times(100 times possible with PRF)
· 75% reduction in Helium
leak generation【In the case of 300mm】· Cost reduction of ¥ 16,000,000 /batch· Throughput improvement for 3,360
wafers➡You can extend the interval of wetcleaning

CCW product introduction(Material, Optional processing)
CCW was developed by International Test Solutions (ITS), USA
Silicon-based polymer Polyimide-based polymer
For （Photo-litho）
For （Etch, PVD）

Appearance of standard product(Silicon-based polymer)
PDMS= Poly(dimethylsiloxane)= R2SiO

POLYIMIDE

3D processing of polymer to be tailored to chuck shape is available

Appearance of 3D processed surfaces:（Only available for Silicon-based polymer)

CCW product introduction(Type)
Size and rate of dust captured
by CCW
1μm： 99.7%
0.5μm ： 75％
0.5～0.2μm ： 50%

Front side : Polymer sideTypeTypes of viscosity of CCW
0.1, 0.2, 0.5, 1.0
Weak ←→ Strong

Back side

Cleaning side

Process

Available wafers(mm)

Heatproof temperature

PRF utilization

Polyimide

Photolitho

200, 300-50～200℃✖

Recyclable times（ref3D process）

15 times(approximate)

Coat

✖

SiliconEtching/Sputtering

200, 300-50～300℃(customizable)

✓
Paste

SiliconEtching/Sputtering/Photolitho

100, 125, 150,
(200, 300)

-50～200℃(300℃)

15 times(approximate)
MAX100 times(with PRF）

✓CCW product introduction(Advantages against for competitors'products)
 It has stronger adhesiveness It has options of stickiness selection
 The polymer has elasticity related to the surface andthe layer thickness
 3D processing is possible
 Operating temperature range is -50 ℃ to 200 ℃（For sputtering, there are also options up to 300 ℃ ） By using PRF (Particle Removal Film), it is possible touse CCW repeatedly by removing dusts and particles
from the polymer surface captured by CCW（Estimatedextend life with PRF : 100 times)
Explanation in page 11

CCW product introduction(Quality)

 It is possible to use CCW in customer's existing wafer
processing environment / equipment
 We manufacture CCW in the clean room environment
 There is no transfer from polymer to chuck during usage(Except in case of polymer breakage due to excessive use) It does not cause heavy metal contamination（TXRF＝ Total reflection fluorescent X-ray analysis)
 There is no release of gases from the polymer within theoperating temperature range（Confirmation with NASA standard ASTM E595)
 The shelf life (shelf life) is 2 years after production

About Particle Removal Film (PRF)
For Etching and Sputtering process

It is a cleaning sheet to use CCW repeatedly
You can reuse CCW up to ~ 100 times
 Can be used for Silicon pasting
Protection film
type only
Cleaning polymer（Strong tackiness）
 13,9,7 inch size
Holding film / sheet 10 pcs 1 set

3. Remove PRF from CCW surface
1. Remove protection film of PRF
2. Crimp PRF on CCW surface with roller 4. Transfer of dusts from CCW surface to PRF
5. Discard PRF sheet

Effect of CCW utilization(Photolithography : ①)
It solves the defective focus due to dusts on the chuckand contributes to the improvement of yield+

200 nm focal defectlocation by alienmatters

Vacuum Chuck
PM type CCW(Polyimide-based)

Remove alienmatters without
opening chamber

200 nm removal offocal defect location byusing CCW

Defect Height(nm)Effect of CCW utilization(Photolithography : ②)

 When dusts/particles larger than 120 nm are detected, CCW performs well
 It is also effective for removing dusts/particles smaller than 100 nm -successfulrate is approximately 80% -Effect of CCW utilization(Etching : ①)
It solves the problem of Helium leakage caused by dusts/particles
on the chuck and contributes to improvement of yield. It also omits the extra
wet cleaning process. Customers can head off the loss of dummy wafers
to a minimum level after PMwaferwafer+ChuckHe

SC type CCW(Silicon based)

ChuckHe

BSPF Fixed
Surface SEM observation
before and after cleaning

Remove alienmatters without
opening chamber

Result：After cleaning with CCW (EtchClean), 99% or more particles
were removed

Helium Flow Rate (sccm)

Effect of CCW utilization(Etching : ②)
Wet cleaning isnecessary 200mm LOGIC – Metal Etching HE flow rate observation during 3 months before and after CCW(Etch Clean) in 3 chamber · environment:
sccm = standard cubic centimeter per minuteEffect of CCW utilization(Etching : ③)
87He Leak Rate (sccm)

Helium Flow Rate (sccm)

9Ch A
Si Dummy

654Ch BSi Dummy

3Ch A
CCW

2Ch B
CCW

101

351015202530354550Wafer # 200mm LOGIC – Metal Etching CCW (Etch Clean) Recovery with 1 to 3 pouring,
Dummy wafer - Recovery with 50 pouring = Shorterrise time / Operating time UpEffect of CCW utilization(Sputtering : ①)
It solves the problem of Helium leakage caused by dusts/particles
on the chuck and contributes to improvement of yield. It also omits the extra
wet cleaning process. Customers can head off the loss of dummy wafers
to a minimum level after PM
wafer

wafer+Chuck
HeSC type CCW(Silicon based)

ChuckHe

Because of the dust on the chuck,deposition uniformity > 5.2%

Surface SEM observation
before and after cleaning

Remove alienmatters without
opening chamber

BSPF FixedDeposition uniformity <2.5% by dust
removal on the chuck by CCW
Chamber opening not requiredEffect of CCW utilization(Sputtering : ②)

Summary The number of dummy wafers to be run after wet cleaning isgreatly reduced. Reference: 50 wafers → 2 to 3 wafers
 Photolithography： It improves the problem of focus defectcaused by hot spot by automatic conveyance.
 Etching：It improves the problem of Helium leakage error
caused by dusts / particles on the chuck by automaticconveyance.
 Sputtering：It improves the problem of Helium leakage error
caused by dusts / particles on the chuck by automaticconveyance. It also contributes to improving in-plane uniformity.
 As a result, customers can eliminate production loss due toequipment downtime occurred in each process.
 CCW can be reused by using in conjunction with PRF.
CCW: 15 times use ➡ With PRF use : 100 times possible(Silicon type for etching and sputtering only)