Silicon Wafer Analyzer

SWA-256M

Contaminants on Silicon Wafers

Typical Organic Contaminants on Si Wafer

- Phthalates, e.g. DEP , DBP , DOP
- Organophorus, e.g. TBP,TCEP,TEP,TPP,TCP
- Antioxidants, e.g. BHT , oxide of BHT
-Siloxanes, e.g.cyclo siloxanes (D3 to D15)
- Adipates, e.g. DBA , DOA
- Amines
- Hydrocarbons

Standards of Organic Contaminants Method

- Silicon Wafer Surface ： ASTM F1982-99
- Outgassing : SEMI E108-0301
- JACA (Japan Air Cleaning Association) No.34-99
- Cleanroom ： ISO TC/209 WG8

(Molecular Contamination)

Schematic of TD-GC/MS

ASTM approved TD-GC standard test method

ASTM F1982-99

- Standard Test Methods for Analyzing
- Organic Contami nants on Silicon
- Wafer Surfaces by Thermal
- Desorpti on Gas Chromatography
- Method A ： Performed on cleaved wafers
- Method B ： Performed on full wafers

SEMI Standard

- SEMI E108-0301
- Test Method for the assessment of Outgassing Organic Contamination
from Minienvironment s using Gas

- Chromatography/Mass Spectrosc opy

SWA-256M Performance with standard sample
(Siloxane D6, BHT, TCEP, DBP, DOP)

SWA-256M Performance with standard sample

Linearity (Siloxane D6, BHT, TCEP, DBP, DOP)

Correlation coefficient (R 2 ) D6: 0.999 BHT : 0.997 TCEP : 0.994 DBP : 0.999 DOP : 0.998

Wafer box

1) Antioxidants

＊ BHT → 2,6-di-tert-butyl-p-Cresol ＊ (Oxidized compounds of BHT)

a) 2,6-di-tert-butyl-p-Benzoquinone
b) 2,6-di-tert-butyl-p-Methaquinone

2) Bridging materials

＊ (Degradated compounds from Bis(t-butyl peroxi-isopropyl)benzene)

a) 1,3-Diisopropenylbenzene
b) p-Isopropenylacetophenone
c) Diacetylbenzene

3) Plasticizers

Phthalic acid ester <(COOR) 2 C 6 H 6 >

＊ DBP →　 Dibutyl phthalate ＊ (Degradated compounds from DBP)

a) Phthalic anhydride b) Butanol

＊ DOP →　 Di(2-ethyl-1-hexyl)phthalate ＊ (Degradated compounds from DOP)
a) Phthalic anhydride
b) 2-ethyl-1-Hexanol
c) C 8 hydrocarbons

4) Unknown

＊ n-butyl-Benzenesulfonamide ＊ 2-Octylthiophene

Photolithography Process, Washing Process

Photolithography Process

1) HMDS → Hexamethyldisilazane

＊ (Degradated compounds from HMDS)

a) Trimethysilanol b) ammonium(undetection)

2) Photo resist solvent
＊ ECA → 2-ethoxyethyl acetate

3) Developing reagent

＊ (Degradated compounds from TMAH → Tetramethylammoniumhydroxide)

a) Trimethylamine
b) Diethylformamide Washing Process

＊ IPA → Isopropanol
＊ Saturated hydrocarbons (C 14 ～ C 20 )

Organic Contaminants on Si Wafer
from Wafer box storage

Clean room

1) Plasticizers

Phthalic acid ester <(COOR) 2 C 6 H 6 >

＊ DBP →　 Dibutyl phthalate
＊ (Degradated compounds from DBP)

a) Phthalic anhydride

b) Butanol

＊ DOP →　 Di(2-ethyl-1-hexyl)phthalate
＊ (Degradated compounds from DOP)

a) Phthalic anhydride

b) 2-ethyl-1-Hexanol c) C 8 hydrocarbons

＊ DEP → Diethyl phthalate
＊ DMP, DIBP, DHP, BBP, DNP Adipic acid ester < (CH 2 ) 4( COOR) 2 >
＊ DBA → Dibutyl adipate
＊ DOA → Di(2-ethyl-1-hexyl)adipate

2) Fire retardants

Phospheric esters

＊ TCEP → Tris(2-chloroethyl)Phosphate
＊ TBP → Tributylphosphate
＊ TEP, TPP, TCP, TMCPP3

3) Sealants

Ring siloxanes Dn=[(CH 3 ) 2 SiO]n>

＊ Trimmers to 15-mers ( Ｄ３ to Ｄ１５ )

4) Unknown

＊ Unsaturated hydrocarbon (C 16 , C 18 )