tool cleanliness characterization for improving...

Tool Cleanliness Tool Cleanliness Characterization for Improving Characterization for Improving

Productivity and YieldsProductivity and Yields

Victor K.F. Chia, [email protected]

Victor K.F. Chia, [email protected]

Reducing Contamination

Agenda¢ Introduction

¢ Tool componentsa Starting material selection and bulk characterizationa Surface cleanliness

• Chemical characterization • Physical characterization

¢ Completed toolsa Tool cleanliness specification

• Particles• Metals• Organics

¢ Tool escalation case study

¢ Conclusion

New and used components

PECVD chamber


Introduction¢ Tool parts cleanliness is an invisible parameter that must be controlled to

enable clean processing ¢ The target contaminants affecting process yields are particles, metals and

organics¢ In the sub-100 nm technology node even irreducible differences in the

components of identical tool chambers can influence yield and mean time between failure (MTBF)

¢ The first line of defense for a fab is to have clean tools for processing, from acceptance trials of the new tool to after each PM. Only with clean tools can a fab maximize its yield by increasing overall equipment productivity and wafer throughput for increased profit margin

¢ This may be accomplished with strict quality control of the supplier chain for starting materials, machine shops, cleaning vendors and contractmanufacturing. In addition, cleanliness specifications must be in place for the BOM.

¢ This presentation reviews cleanliness specifications for components and completed tools and characterization methods for verifying their cleanliness


Starting MaterialsRequirements¢ The materials used in the BOM, including

lubricants and grease, must be compatible to its function and cleanliness requirements

¢ Multi-alloy parts must be cleanable¢ Bulk material characterization is important as the

root source of wafer contamination may be from the bulk of the material; no amount of cleaning will remove this contamination source

Metals Al Ni SST Mo Ti Ta Cu / Cu Alloys

Coatings Ni Plating Au Plating Powder Coating Paint Alodine Anodized Zn

Plastics PEEK PTFE Polyimide Polyethylene Kapton Viton Calrez

Ceramics Alumina Glass Saphire DLC Quartz

AssembliesWelded

Aluminum

Welded Steel Alloys

Brazed Bonded Flex Circuit

Complex Wafer Arm Assembly

Common materials used in build of materials (BOM)


Starting Materials Characterization

¢ O-rings with inorganic fillers like SiO2, BaSO4, ZnO, C or TiO2 lasts about 6,000 wafer counts before particulation issues occurs

¢ O-rings using organic filled material can reach upwards of 20,000 wafer counts with reduced number of metallic particles escalations

Layer 1

Layer 4

Substrate

Layer 2

Layer 3

80E80E80E80E

Mass Spectrum

0

100000

200000

300000

400000

500000

0 20 40 60 80 100 120 140 160 180 200m/z (amu)

Sig

nal

Inte

nsi

ty (

c/s)

O-Ring Defect

S

Fe

Mn

I

C

Ni Mo

Metals on wafer using VPD ICP-MC

Mass Spectrum

0

20000

40000

60000

80000

100000

0 10 20 30 40 50 60 70 80m/z (amu)

Sig

nal Int

ensity

(c/s

)

Defect Inclusionthat is only visible under UV light

Si

OX

Y

Quartz

Si

O XY

100

1000

10000

100000

-1 0 1 2 3 4

Sampling Depth in µm

ICP

-MS

Sig

nal

Inte

nsi

ty (c

/s)

Iron (Fe)

Copper (Cu)

Zinc (Zn)

wafer

Fe

Cu

Zn

Fe

“clean”

“dirty”Ceramic

Metal or metal alloy whose melting temperature is considerably lower than the sintering temperature of the ceramic body are used to fill voids in the ceramic to achieve a particular physical property –conduction, brazing, etc.

Laser ablation ICP-MS

wafer

O-Ring

O-ring defect

FeMoS

I


Metal Escalation¢ Escalation: Metal contamination

¢ Verify root cause: fix short and replace ceramic rods

¢ Escalation resolved

Element DL1 2 3 4 5 6 7 8 9 10 11 12

Al 50 130 590 58000 5260 420 590 1500 12500 15000 2300 350 730Cr 50 * * * * * * * * * * * *

Fe 50 * * * * * * * 1200 1000 3600 300 *

Mg 50 270 310 460 1200 12000 550 * 4500 1350 * 1000 *

Ni 50 * * 150 * 760 * * 1500 560 590 * *

K 50 300 200 600 200 400 1800 300 1500 8100 300 200 250Na 50 1400 1200 6000 6200 750 6800 1200 1900 50000 1200 400 1200

Area 1 Area 2 Area 3 Area 4

Metal wipe test results

ng/cm2

¢ Contamination identification:VPD ICP-MS

ElementDL E10 at/cm2

Al 0.3 250Ca 0.3 110Cr 0.2 24Cu 0.05 0.82Fe 0.05 86Mg 0.1 61Ni 0.05 0.7K 0.3 40Na 0.3 77Zn 0.1 13

300mm Wafer

VPD ICP-MS Results

BULK CONCENTRATION(atoms/cm3)

Element Ceramic A Ceramic B Ceramic CBa 3.0E16 9.1E15 2.2E13B 1.2E18 1.7E16 6.3E15Ca 1.1E19 9.1E17 6.6E15Co 8.6E14 1.2E13 2.4E13Cu 6.1E15 2.1E16 1.7E13Fe 1.6E17 2.9E16 3.8E15Li 3.3E16 1.2E15 NDMg 7.7E16 1.8E17 3.4E15Mn 3.1E15 2.8E15 7.5E13Ni 1.7E16 1.0E15 3.4E13K 1.8E18 1.0E17 4.4E14Na 5.3E18 1.1E18 3.5E15Sr 8.8E15 2.8E15 1.7E13Sn 2.8E15 1.4E13 1.1E13Ti 1.2E19 7.4E15 1.1E15W 6.1E15 5.0E14 5.0E13Zn 2.0E16 1.1E18 1.4E15Zr 7.7E15 6.0E16 4.0E13

SARIS (10 µm) of ceramic insulator rods

Partitioning Tests

¢ Partitioning test: metal wipe test¢ Hypothesis: micro-arcing


Starting Materials Characterization

RED: material that may outgas

Part Description Material/Composition

Cable CoaxialConductor Material: Silver Plated Copper Covered Steel (SPCCS); Insulation Material: Tetrafluoroethylene (TFE); Outer Shield Material: Silver Plated Copper; Outer Jacket Material: Fluorinated Ethylene Propoylene

Connector for Coaxial PlugShell: Brass; Plug Body: Brass; Cable Clamp, Inner Sleeve, Washer or Nuts: Brass; Male Crimp Contacts: Bronze; Female Crimp Contacts: Bronze

Connector for Coaxial Plug - 50 Ohm

Outer Shell: Brass, Stainless Steel, Aluminum Alloy, PEEK; Sealing Resin: Epoxy; Grounding Crown: Bronze, Beryllium Copper, Stainless Steel; Latch Sleeve: Special Brass, Stainless Steel; Locking Washer: Bronze; Hexagonal or Round Nut: Brass, Stainless Steel, Aluminium alloy; Other Metallic Components: Brass, Stainless Steel; O-Ring and Gaskets: Silicone

Cable CoaxialConductor Material: Silver Plated Copper Covered Steel; Insulation Material: Tetrafluoroethylene (TFE); Outer Shield Material: Silver Plated Copper Covered Steel; Outer Jacket Material: Fluorinated Ethylene Propylene

Connector Socket, Open End Contact Material: Copper Alloy; Contact Underplating: Nickel; Insulation Material: Glass Filled Polyester (PBT)

Sensor, Light/Dark Materials: Polybutylene Phthalate (PBT); Cover: Polycarbonate; Emitter: Polycarbonate

Wire, 28 AWG, Black * Conductor Material: Silver Plated Copper; Insulation Material: Tetrafluoroethylene (TFE)

Connector, Socket 26 Position, Open EndContact Material: Copper Alloy; Contact Underplating: Nickel; Insulation Material: Glass Filled Polyester (PBT)

Shrink Tubing, 3/32 ID, Kyanr, Clear Polyvinylidene Fluoride

Wire, 28 AWG, Black * Conductor Material - Silver Plated Copper, Insulation Material: Fluorinated Ethylene Propylene (FEP)

Cable, High Voltage, 22 AWG, Stranded Silver Plated Conductor, Overlapping tapes of GoreTM Corona Resistant (PTFE)

Terminal Ring, 12-10 AWG Electrolytically Refined Copper

Organic outgassing sources


Bulk Organic CharacterizationThermal Desorption Gas Chromatography Mass Spectrometry (TD-GCMS)

_ _ _Carrier Gas Inlet

Hot Sample Tube(400OC)

Cold Trap

Carrier Gas Inlet

GCAnalyticalColumn

To Mass Detector

Primary (Tube) DesorptionDesorb Flow

¢ In-instrument outgassinga Tenax tubea For medium to high outgassing material

¢ Off-line outgassinga Quartz tubea Larger sample to increase detection limita For low outgassing material


Surface Cleanliness of Tool Components Target contaminants depend on the history of the part¢ Starting material

a Gross contaminationa Not a concern as the material will be machined and later cleaneda Bulk contamination is more critical

¢ Machined parta Major contamination is from machine oil, metal cross-contamination,

water and solvent residue, oven, etc.a Machine shops are not semiconductor clean environmentsa Contaminants of concern: Organic > Particle > Metal > Anion

¢ After Precision cleaninga Minor contaminationa Typically from handling, environment, packaging, etc.a Contaminants of concern: Metal > Particle > Organic > Anion

Trend is for machine shops to pre-clean

in-house, outsource Precision

Cleaning and send parts

directly to the customer

a) Precision cleaning is defined as “The removal of undesirable contaminants to a pre-determined measurable standard without introducing new contaminants or changing the surface integrity”

b) Precision cleaning dictates the tool BOM must have a cleanlinessspecification


Surface Contamination Characterization

¢ Applicationa Machined parts – coupons and first articlea New and used parts after Precision Cleaning

¢ Specificationa Effective in removing surface contamination for analysisa Must be damage-free with minimal material lossa Performed on small and large parts (300mm and 450mm)a Part may be returned to the field after testing

¢ Current test methods involving wet chemistrya Imparts minimal damage to the surfacea No restriction on part sizea Effective in removing metals, anions and organic residues since they have a

high solubility in liquid chemistriesa High efficiency in particle removal

• Adjusting the surface zeta potential (e.g. pH) to reduce the adhesion force• Reducing megasonic energy to improve the particle removal performance and to

reduce damage


Chemical Surface Characterization

KEY1. Metal: whole surface extraction2. Metal: UPW extraction efficiency less than using acid

ü No surface damage3. Metal: localized surface extraction using acid

ü Can be performed directly on tool component surface4. Organic: solvents to extract organic residue and UPW/TOC5. Organic: weight of NVR and organic identification6. Ionic: whole surface extraction7. Particle: whole surface particle counting and identification

Test methods are often referredto as Leach or Extractable

Acid extraction & ICP-MS 1

UPW extraction & ICP-MS 2

Drop scan etch & ICP-MS 3

Solvent extraction & GC-MS 4

Solvent extraction & NVR/FTIR 5

Ionic UPW extraction & Ion Chromatography 6

Particle UPW extraction & LPC (SEM-EDS) 7

Metal

Organic

SEMICONDUCTORPROCESS OPTIMA

Wafer ProductionThermal Oxidation/Film

PhotolithographyEtch

Doping/Ion ImplantDielectric Deposition

CMP

Non-Destructive

test procedures

Ceramic showerhead

8”

SEM with large sample chamber


Surface Extraction of Components¢ Provides surface cleanliness verification and quantification of contaminants

a Compare vendorsa Qualify components to a cleanliness specificationa Ensure components and coatings are compatible to a process – temp, exposure time,

acid/alkali, HV, etc.a Lot to lot quality control

¢ General rulea A less aggressive leach results in lower detectable contaminant levela A more aggressive leach results in higher detectable contaminant level

¢ Static leach conditionsa Component is soaked in UPW or chemical solutiona Standard test condition

• Ambient temperature, UPW and short extractiontime of 1h to 1 day

a Semi-Aggressive• Elevated temperature <50C, UPW and short

extraction time of 1-2ha Aggressive

• High temperature, extended extraction time and/or use of chemicals • Chemical for 7 days at ambient temperature• UPW at 85C for 7 days (SEMI F-57)

Ceramic rings


Surface Extraction of Packaging Films

¢ Rule of thumb, the cleanliness level of packaging films should be at least 3-5x lower than the cleanliness specifications of the parts to be packaged

¢ Natural and antistatic PE generally exhibit acceptable levels of ionic cleanliness; generally shown to also be oil and amine-free

¢ Most available films, including natural PE, are not adequate for packaging tool parts requiring very low levels of hydrocarbon contaminants. FEP is acceptable but costs 15x more than PE.

¢ Bagging requirements:a Double bagging for all parts except tool parts (robotic blades, handling systems, chucks) that

are exposed to the wafer must be triple bagged a Bagging material must cover all outer tool surfaces

10

50

40

30

20

Ionic Species

F- Cl- NO3- SO4

- Na+ NH4 + K+ Mg2+

Antistatic PE

Natural PE

Antistatic Nylon

Ca2 +

Lin S and Graves S, Micro, October, 1998

Sur

face

Con

c. (x

1012

mol

/cm

2 )


Metal AES 1

TXRF 2

VPD ICP-MS 3

SurfaceSIMS 4

TOF-SIMS 5

Organic Full Wafer Outgassing TD-GCMS 6

TOF-SIMS 7XPS 8

Ionic XPS 9Particle FE-AES 10

SEMICONDUCTORPROCESS OPTIMA

Wafer ProductionThermal Oxidation/Film

PhotolithographyEtch

Doping/Ion ImplantDielectric Deposition

CMP

Physical Surface Characterization

KEY1. AES: 30-50Å, at% DL, elemental survey, conducting surface2. TXRF: 30-50Å, 109-1015 at/cm2, elemental survey, flat surface 3. VPD ICP-MS: SiO2, 107-1015 at/cm2, elemental survey4. SurfaceSIMS: any depth, 108-1015 at/cm2, elemental specific5. TOF-SIMS: ML, 107-1015 at/cm2, elemental survey, any surface 6. Full Wafer Outgassing: ng/cm2, organic survey7. TOF-SIMS: monolayer, ng/cm2, organic survey, any surface8. XPS: 30-50Å, at% DL, elemental/chemical state survey,

non-conducting surface 10. FE-AES: 10nm spatial resolution for elemental characterization

Other¢ UV (black) light: visual inspection for residue polymer on the surface¢ Profilometry: surface roughness and surface layer thickness (Fisherscope)

Destructive techniques

* non-destructive

wafer test

*

Mostly used for coupons, wafers and R&D

Sectioning ceramic showerhead

**

X-section of opening


Tool Particle Specification

Wafer Front Sidea Wafer Back Sidea Tool Surfaceb

>90 nm

90 nm

65 nm

45 nm

Full pipeline test, 6 wafers, 150 cycles, KLA SP2

Particle SpecificationTechnology Node Analytical Test

Non-Critical Surface≤10/in2 @ 0.3 µm

Critical Surface≤1/in2 @ 0.3 µm0.2 @ 90 nm

(0.0002/cm2 pwp)

Full Contact<1500 @ 90 nm (2.8/cm2 pwp)

Low Contact<500 @ 90 nm

Edge Contact<20 @ 90 nm

a) Tool with closable holes for insertion of sample heads for airborne qualification purposes and FA

b) Particles on tool component surfaces and skin shall be measured using a surface particle detector

Mainframe Surfaces

(particles/in² @ 0.3 µm)

Painted = <10-80Granite = <10-95Anodized = <10-60Aluminum = <15-90Plexiglass = <10-90

Location Area 0.3 um 0.5 um 1 um 5 um 10 umChamber lid 15 0.04 0 0 0 0Chamber lid 16 0.04 0 0 0 0

Location Area 0.3 um 0.5 um 1 um 5 um 10 umChuck/back 10 0.08 0 0 0 0Chuck/front 11 0 0 0 0 0Stage/rear 12 0.21 0.13 0 0 0Stage/front 13 0.08 0 0 0 0

Nest/low surface 6 0.17 0.13 0.08 0 0Nest/high surface 7 0.13 0.08 0 0 0Transfer arm/front 8 0.04 0.04 0.04 0 0Transfer arm/back 9 0.88 0.79 0.58 0 0

Location Area 0.3 um 0.5 um 1 um 5 um 10 umOff LL 1 0.21 0 0 0 0Bridge 2 6.92 3.54 1.6 0.08 0.04

Front LL 3 2.38 1.83 0.96 0.42 0.331

23

45

8

9

10 1

113

12

15

16

¢ The Al/Ti particle originating from an interaction of an etch by-product of the TiN adhesion layer and the process chamber hardware

Ti

Al

Si


Tool Metal SpecificationTechnology Node Analytical Testa Metal Specificationb

Full Pipeline test, 6 wafers by 100 cycles

>90 nm VPD-ICP-MS ≤5E11 at/cm2 per metal

90 nm VPD-ICP-MS ≤1E10 at/cm2 per metal



a) VPD ICP-MS detects Ca, K, Na, Al, Fe, Cr, Ni, Zn, Li, Be, Mg, V, Mn, Co, Ga, Sr, Zr, Mo, Cd, Sn, Sb, Ba, Ti, Y, Rb, In, Ce, Th, U, Cu.

b) Target metals include Gp 1 metals (Fe, Ni, Cu, Cr, Co, Hf, and Pt; can dissolve in Si and form silicides) and/or Gp 2 metals (Ca, Ba, Fe and Sr; GOI killers)

SIMS PROFILE

STANDARD TXRF

=

SurfaceSIMS TOF

High Detection Low Detection

Wafer

SARIS

Gross Contamination Process Tool Uncleaned CleanedMetal


Tool Organic Specification

a) ASTM F1982-99 "Standard Test Method for Analyzing Organic Contaminants on Silicon Wafer Surfaces by TD-GC.“ This method is designed to sample semivolatile organic airborne molecular contamination adsorbed onto the polished face of the Si wafer

b) Wafer side specificc) >10 ng/cm2 affects

adhesion¢ 2 ng/cm2 ˜ 0.1 ML¢ ML ~5Å¢ ML ~ 1015 at/cm2

Technology Node Analytical Testa Organic Specificationb, c, d

Organic component Sum ≥C7tested in Dynamic Mode

>90 nm ≤20 ng/cm2

90 nm ≤20 ng/cm2

65 nm ≤15 ng/cm2

45 nm ≤10 ng/cm2

1) Load Lock Partition test: 1x2 wafers, 200 cycles (100 cycles each), ~ 30 mins exposure/wafer.2) Organic Pipeline test: 2x2 wafers, 120 cycles (30 cycles each), ~20 mins exposure/wafer.3) Full wafer outgassing by TD-GC-MSa

SEMI MF1982-1103Full wafer outgassing TD GC-MS

Figure 1

Sample ID: CHUCK- Al2O3, 1/22/07 (19:00 HOURS AT 1.2 x 10- 7 TORR)

5.00 10.00 15.00 20.00 25.00 30.00 35.000

2000000400000060000008000000

1e+071.2e+071.4e+071.6e+071.8e+07

2e+072.2e+072.4e+072.6e+072.8e+07

3e+073.2e+073.4e+073.6e+073.8e+07

4e+074.2e+074.4e+074.6e+074.8e+07

5e+07

Time-->

AbundanceIon 33.00 (33.00 to 700.00): 70052605.D

d8-TOLU

ENE (INTE

RNAL ST

ANDARD)

C8-H

YDROCARBONS

CYCLO

(Me 2S

iO) 3

CYCLO

(Me 2S

iO) 4

+ ETH

YL H

EXANOL

CYCLO

(Me 2S

iO) 5

FLUOROALKYL ETHER (m/z:69,119,169,285,335)

CYCLO

(Me

2SiO) 6

CYCLO

(Me 2SiO) 7

CYCLO

(Me 2S

iO) 8

CYCLO

(Me

2SiO) 9

CYCLO

(Me 2S

iO) 10

CYCLO

(Me 2S

iO) 11

POSSIBLE

CYCLO

(Me

2SiO) 12

Figure 1

Sample ID: CHUCK- Al2O3, 1/22/07 (19:00 HOURS AT 1.2 x 10- 7 TORR)

5.00 10.00 15.00 20.00 25.00 30.00 35.000

2000000400000060000008000000

1e+071.2e+071.4e+071.6e+071.8e+07

2e+072.2e+072.4e+072.6e+072.8e+07

3e+073.2e+073.4e+073.6e+073.8e+07

4e+074.2e+074.4e+074.6e+074.8e+07

5e+07

Time-->

AbundanceIon 33.00 (33.00 to 700.00): 70052605.D

d8-TOLU

ENE (INTE

RNAL ST

ANDARD)

C8-H

YDROCARBONS

CYCLO

(Me 2S

iO) 3

CYCLO

(Me 2S

iO) 4

+ ETH

YL H

EXANOL

CYCLO

(Me 2S

iO) 5

FLUOROALKYL ETHER (m/z:69,119,169,285,335)

CYCLO

(Me

2SiO) 6

CYCLO

(Me 2SiO) 7

CYCLO

(Me 2S

iO) 8

CYCLO

(Me

2SiO) 9

CYCLO

(Me 2S

iO) 10

CYCLO

(Me 2S

iO) 11

POSSIBLE

CYCLO

(Me

2SiO) 12

Cyclo(Me 2SiO)

Cyclo(Me 2SiO)Fluroalkylether

Fluroalkylether

Flu

oro

alk

yl

Eth

er

RGA

Cycl

o(M

e2S

iO) 3

Cycl

o(M

e2S

iO) 5

Cycl

o(M

e2S

iO) 6

Cycl

o(M

e2S

iO) 7

Cycl

o(M

e2S

iO) 8

Cycl

o(M

e2S

iO)

10

Cycl

o(M

e2S

iO) 1

2

Cycl

o(M

e2S

iO) 4

+ E

thyl

Hexan

ol

Cycl

o(M

e2S

iO) 9

Cycl

o(M

e2S

iO)

11

Full Wafer TD-GCMS


Tool Escalation Case Study

TOOL ESCALATIONTOOL

OBSERVATIONSFAILURE ANALYSIS ROOT CAUSE REMEDY

High SMC carbon level exceeding tool acceptance level of 2 at% by XPS

7 carbon at% on witness wafer

Full Wafer TD-GCMS to identify AMC-MC species. FTIR and TOF-SIMS to identify lubricant compound.

Excess lubricant in toolRemove excess lubricant

High Cl TXRF level exceeding 5E10 at/cm2 spec for acceptance

5E13 Cl at/cm2 on witness wafer

Determine inorganic Cl using IC or organic Cl using GCMS. O-Cl confirmed followed by species identification using Full Wafer TD-GCMS in dynamic testing mode.

Foam isolation padsTD-GCMS verification of alternative materials

High Pb level by VPD ICP-MS exceeding 5E10 at/cm2 tool SPC

5E11 Pb at/cm2 on witness wafer

VPD ICP-MS monitoring was critical as Pb is not detected by TXRF using W source. Isolation experiments identified root source.

City water source used during manufacturing of PVDF tubing

Hot DIW flush of tubing

High replacement rate of beam aperture on ion implanter

Reduced beam current

SEM-EDX identifies organo-Si as contaminant on aperture. TD-GCMS identifies organic species.

Outgassing of Gelpak aperture packaging

TD-GCMS verification of alternative packaging

Metal spec is 5E10 at/cm2 by TXRF

1Residual HCl from insufficient

rinsing??

2

INORGANIC ORGANIC

SARIS/SEM-EDX First “look” tool

LOW CONC.

VPD ICP-MSTXRF, VPD TXRF

UPW – ICUPW-ICP-MSdAcid-ICP-MS

TOF-SIMSQuad-SIMS

LOW CONC.

TOF-SIMSFW TD-GCMS

TD GC-MS

4Static wafer show no Cl by TXRFDynamic wafer testing show Cl

3

Pad compresses and outgasses at edge

6Blue pad outgassBlk pad not outgas

7

Cl

Flame retardant5

This is a difficult problem to solve because no one did anything wrong. In fact, everyone involved did what they thought was the right thing to expedite the PM and keep on schedule.

8


Organic Tool Optima™Escalation¢ Performance¢ Contamination

a >2 at% carbon (XPS)a >5E10 Cl atoms/cm2 (TXRF)

Partitioning Test¢ Select materials, inside and

outside of the tool, to test for organic outgassing

a Identify and quantify organic species

¢ Wipe test for local testing of tool components

Contamination Identification¢ SMC-SMOrg - FW TD-GCMS

a Static: 2 to 24 h exposurea Dynamic: 20 to 100 cyclesa Identifies and quantifies organic

speciesa Ranks organic concentrations into

groups – low (C7-C10), medium (>C10 – C20) and high boilers (>C20)

Resolve Escalation¢ Repeat performance or

contamination test

Verify Root Cause¢ Repeat static or dynamic

wafer exposure¢ Perform FW TD-GCMS


Conclusion¢ Tool contamination is a major cause of many fab escalations¢ High yield processing requires clean tools and clean manufacturing

procedures. This dictates there must be cleanliness specification for in-tools, precision cleaning, packaging and on the process floor (Ex: housekeeping cleanliness specifications)

¢ Unfortunately, cleanliness specifications are often lacking and this impounds the difficulty to resolve contamination escalations, both in the tool and on the process floor

¢ Bulk and surface contamination of starting material and tool components are equally important

¢ Target contaminants differ for a part and depends on its life cycle – from raw material, coupon, first article, new part, used part, etc.

¢ Non-destructive chemical characterization is possible on production tool parts¢ Destructive physical characterization on production tool parts is an option if you

are willing to sacrifice the part¢ Cleanliness verification of tool BOM is instrumental to optimizing process

yields. Advanced technology node processes require stringent cleanliness specifications, lower analytical detection limits and clean handling technique

tool cleanliness characterization for improving...

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