semi合集-English.pdf - 第6730页

SULFURIC ACID SEMI C44-0301 © SEMI 1978, 20 01 3 8.7.5 All Other Elements — In a clea n e nvironmen t, place 100 g of su lfuric acid in a quartz crucible. Slowly evaporate on a hot plate av oiding lo ss of sample b y eff…

100%1 / 7923
SEMI C44-0301 © SEMI 1978, 2001 SULFURIC ACID2
minutes. Cool and transfer to a tightly-capped glass bottle for
storage.
8.4 Nitrate — Prepare the following solutions:
Sample Solution A: Cautiously add 27 mL (50 g) of sample
to 1.0 mL of water, dilute to 50 mL with
brucine sulfate reagent solution and
mix.
Control Solution B: Cautiously add 27 mL (50 g) of sample
to 1.0 mL of the standard nitrate
solution containing 0.01 mg of nitrate
ion (NO
3
) per mL, dilute to 50 mL with
brucine sulfate reagent solution and
mix.
Blank Solution C: Use 50 mL of brucine sulfate reagent
solution.
8.4.1 Heat the three solutions in a preheated (boiling)
water bath for 10 minutes. Cool rapidly in an ice bath to
room temperature. Set a photometer at 410 nm and,
using 1-cm cells, adjust the instrument to read zero
absorbance with Blank Solution C in the light path, then
determine the absorbance of Sample Solution A. Adjust
the instrument to read zero absorbance with Sample
Solution A in the light path and determine the
absorbance of Control Solution B. The absorbance of
Sample Solution A should be no greater than that
Control Solution B.
8.5 Phosphate — Evaporate 11 mL (20 g) of sample
to dryness in a platinum dish in a hood. Dissolve the
residue in 25 mL of 0.5 N sulfuric acid. Add 1 mL of
ammonium molybdate reagent solution and 1 mL p-
(methylamino)phenol sulfate reagent solution. Allow to
stand at room temperature for 2 hours. Any blue color
produced should be no greater than that produced when
0.01 mg of phosphate ion (PO
4
) is treated as the sample.
8.6 Arsenic and Antimony (as As) — To 109 mL (200
g) of sample in a beaker, add 5 mL of nitric acid and
evaporate to about 10 mL in a hood. Cool. Cautiously
add 10 mL of water, and again evaporate to about 5
mL. Cool, and cautiously wash into a generator flask
with water to make a volume of 35 mL. Proceed as
described in General Method for Arsenic (and
Antimony) under SEMI C1, Section 3.4.5, starting with
the first sentence which begins: “Swirl the flask...”
Any red color in the silver diethyldithiocarbamate
solution from the sample should be no greater than that
of the standard containing 0.001 mg of arsenic (As).
8.7 Trace Metal Analysis
8.7.1 Gold (Au) — Analyze by graphite atomic
absorption using the manufacturer's recommended
procedure. This technique has been shown to give
satisfactory results using a 1:4 dilution and Zeeman
background correction. Each laboratory must determine
the appropriate dilution and background correction for
its instrument to meet the specification limit.
8.7.2 The following method has given satisfactory
results in determining trace metal impurities at the
value specified for each of the following trace metals:
aluminum (Al), boron (B), calcium (Ca), chromium
(Cr), copper (Cu), iron (Fe), lead (Pb), magnesium
(Mg), manganese (Mn), nickel (Ni), potassium (K),
sodium (Na), tin (Sn), titanium (Ti), and zinc (Zn).
Alternate methods may be used as long as appropriate
studies demonstrate recovery between 75–125% of a
known sample spike for half of the value of each
specified item.
8.7.3 Special Reagents
8.7.3.1 Water — The water used for all the dilution,
calibration and standards should meet at a minimum the
criteria for Type E1.1 in ASTM D5127 in regard to
cation analysis.
8.7.3.2 Indium Internal Standard — Make up the
indium intenal standard solution to a concentration of
20 µg/mL (ppm) from the appropriate concentrated
indium standard solution.
8.7.3.3 Nitric Acid, Ultrapure — Use nitric acid
specified for ultra low metal ion content.
8.7.3.4 1% Nitric Acid Solution — Dilute 10 mL of
ultrapure nitric acid to 1 L using water meeting the
criteria for Type E1.1 in ASTM D5127.
8.7.3.5 2% Nitric Acid Solution — Dilute 20 mL of
ultrapure nitric acid to 1 L using water meeting the
criteria for Type E1.1 in ASTM D5127.
8.7.3.6 Hydrochloric Acid, Ultrapure — Use
hydrochloric acid specified for ultra low metal ion
content.
8.7.3.7 2% Hydrochloric Acid Solution — Dilute 20
mL of ultra-pure hydrochloric acid to 1 L using water
meeting the criteria for Type E1.1 in ASTM D5127.
8.7.4 Sample Preparation
8.7.4.1 Boron — In a clean environment, dilute 1.00 g
sample with 15.0 g of Type E1.1 water and add 15 µL
of the indium internal standard. Run a reagent blank.
8.7.4.2 Tin — In a clean environment, place 100 g of
sulfuric acid in a quartz crucible. Slowly evaporate to
dryness on a hot plate avoiding loss of sample by
effervescence or spattering. Cool. Add 2 mL of high
purity 12 M hydrochloric acid and 10 mL of water.
Cover, and digest on the hot plate for 10 minutes. Cool.
Transfer quantitatively to a 50 mL volumetric flask
using water for rinsing and dilution to volume. Run a
reagent blank.
SULFURIC ACID SEMI C44-0301 © SEMI 1978, 20013
8.7.5 All Other Elements — In a clean environment,
place 100 g of sulfuric acid in a quartz crucible. Slowly
evaporate on a hot plate avoiding loss of sample by
effervescence or spattering until approximately 2 mL of
liquid remains. Cool. Add carefully, 1 mL of high
purity, 70% nitric acid. While maintaining volume,
carefully warm several minutes to dissolve any residue.
Cool. Transfer quantitatively to a 50 mL volumetric
flask using 2% nitric acid and dilute to volume. Run a
reagent blank.
8.7.6 Analysis — Using the prepared solutions and
blanks, analyze boron by inductively coupled plasma
mass spectrometry (ICP/MS). Using the acid sample
and reagent blank, analyze group I elements by flame
atomic absorption spectroscopy. Analyze all other
elements by plasma emission spectroscopy.
NOTE 4: Analysis of dilute sulfuric acid can produce rapid
corrosion of nickel cones commonly used in inductively
coupled plasma mass spectrometry, platinum cones should be
considered as alternative when performing this analysis.
9 Grade 2 Procedures
NOTE 5: Each laboratory is responsible for verifying the
validity of the method within its own operation.
9.1 Non-Metal Impurities — See Section 8, which
contains procedures for the following tests:
Assay
Color (APHA)
Chloride
Nitrate
Phosphate
9.2 Trace Metals Analysis
9.2.1 The following method has given satisfactory
results in determining metal ion impurities at the values
specified for each of the following metals: aluminum
(Al), antimony (Sb), arsenic (As), barium (Ba),
beryllium (Be), bismuth (Bi), boron (B), calcium (Ca),
chromium (Cr), cobalt (Co), copper (Cu), gallium (Ga),
germanium (Ge), gold (Au), iron (Fe), lead (Pb),
lithium (Li), magnesium (Mg), manganese (Mn),
molybdenum (Mo), nickel (Ni), niobium (Nb),
potassium (K), silver (Ag), sodium (Na), strontium (Sr),
tantalum (Ta), tin (Sn), titanium (Ti), vanadium (V),
zinc (Zn), and zirconium (Zr). Alternate methods may
be used as long as appropriate studies demonstrate a
recovery between 75–125% of a known sample spike
for half of the value of each specified element.
9.2.2 Special Reagents
9.2.2.1 Nitric Acid, Ultrapure — Use nitric acid
specified for low metal ion content.
9.2.2.2 1% Nitric Acid Solution — Dilute 10 mL of
ultrapure nitric acid to 1 L using water meeting the
criteria for Type E1.1 in ASTM D5127.
9.2.2.3 Water — The water used for all the dilution,
calibration and standards should meet at a minimum the
criteria for Type E1.1 in ASTM D5127 in regard to
cation analysis.
9.2.2.4 Indium Internal Standard — Make up the
indium intenal standard solution to a concentration of
20 µg/mL (ppm) from the appropriate concentrated
indium standard solution.
9.2.3 Sample Preparation
9.2.3.1 Chromium, Cobalt, Lithium, Manganese,
Nickel, Titanium, Vanadium, and Zinc — In a clean
environment, place 1.00 g of sample into a clean quartz
dish. Slowly evaporate on a hot plate to dryness
avoiding loss of sample by effervescence or spattering.
Dissolve the residue with 5 mL of the 1% nitric acid
solution by heating on a hot plate at low temperature for
several minutes. Cool to room temperature, dilute to 15
mL with 1% nitric acid, add 15 µL of the indium
internal standard, mix well. Run a reagent blank.
9.2.3.2 All Other Elements — In a clean environment,
dilute 1.00 g sample with 15.0 g of Type E1.1 water
and add 15 µL of the indium internal standard. Run a
reagent blank.
9.2.4 Analysis
9.2.4.1 Using the prepared solutions and blanks,
analyze sodium, potassium, calcium and iron by
graphite furnace atomic absorption (GFAA) and the
remaining elements by inductively coupled plasma
mass spectrometry (ICP/MS). For calibration, the
standards are made up with the 1% nitric acid solution
and the indium internal standard such that the final
indium concentration is 20 ng/g. For boron and
tantalum, the standards for calibration must be matrix
matched with equal amounts of sulfuric acid certified to
have both elements below 1 µg/mL in the concentrated
acid.
NOTE 6: Analysis of dilute sulfuric acid can produce rapid
corrosion of nickel cones commonly used in inductively
coupled plasma mass spectrometry, platinum cones should be
considered as alternative when performing this analysis.
10 Grade 3 Procedures
10.1 This section does not apply to this chemical.
11 Grade 4 Procedures
11.1 This section does not apply to this chemical.
SEMI C44-0301 © SEMI 1978, 2001 SULFURIC ACID4
12 Grade 5 Procedures
12.1 This section does not apply to this chemical.
13 VLSI Grade Procedures
13.1 Specific procedures for this grade do not exist.
Refer to Sections 8 and 9 for available procedures.
14 Tier A Procedures
14.1 This section does not apply to this chemical.
15 Tier B Procedures
15.1 Standardized test methods are being developed
for all parameters at the purity levels indicated. Until
standardized test methods are published, test
methodology shall be determined by user and producer.
The Chemical Reagent Committee considers a test
method to be valid only if there is a documented
recovery study showing a recovery of 75–125%.
Recovery is for a known sample spike at 50% of the
specified level.
16 Tier C Procedures
16.1 Standardized test methods are being developed
for all parameters at the purity levels indicated. The
Process Chemicals Committee considers a test method
to be valid if there is a documented recovery study
showing a recovery of 75–125%. Recovery is for a
known sample spike at 50% of the specified level.
17 Tier D Procedures
17.1 This section does not apply to this chemical.
Table 1 Impurity Limits and Other Requirements for Sulfuric Acid
Previous SEMI Reference # C1.16-96 C7.8-94 C11.5-94 C8.8-92
Grade 1 Grade 2 VLSI Grade Tier B Tier C
(Specification) (Specification) (Guideline) (Guideline) (Guideline)
Assay (H
2
SO
4
) 95.0–97.0% 95.0–97.0 % 95.0–97.0% 95.0–97.0% 95.0–97.0%
Color (APHA) 10 max 10 max 10 max 10 max 10 max
Residue after Ignition -- -- 3 ppm max -- --
Chloride (Cl) 0.1 ppm max 100 ppb max 0.1 ppm max 50 ppb max 50 ppb max
Nitrate (NO
3
) 0.2 ppm max 200 ppb max 0.2 ppm max 100 ppb max 100 ppb max
Phosphate (PO
4
) 0.5 ppm max 500 ppb max 0.5 ppm max 100 ppb max 100 ppb max
Matters Reducing KMnO
4
(as O)
-- -- 2 ppm max -- --
Aluminum (Al) 0.2 ppm max 10 ppb max 0.02 ppm max 1 ppb max 100 ppt max
Ammonium (NH4) -- -- 1 ppm max -- --
Antimony (Sb) -- 5 ppb max -- 1 ppb max 100 ppt max
Arsenic (As) -- 10 ppb max -- 1 ppb max 100 ppt max
Arsenic and Antimony (as As) 0.005 ppm max -- 0.01 ppm max -- --
Barium (Ba) -- 10 ppb max 0.01 ppm max 1 ppb max 100 ppt max
Beryllium (Be) -- 10 ppb max 0.01 ppm max 1 ppb max --
Bismuth (Bi) -- 10 ppb max 0.05 ppm max 1 ppb max --
Boron (B) 0.02 ppm max 20 ppb max 0.02 ppm max 1 ppb max 100 ppt max
Cadmium (Cd) -- 10 ppb max 0.01 ppm max 1 ppb max --
Calcium (Ca) 0.3 ppm max 10 ppb max 0.05 ppm max 1 ppb max 100 ppt max
Chromium (Cr) 0.2 ppm max 10 ppb max 0.01 ppm max 1 ppb max 100 ppt max
Cobalt (Co) -- 5 ppb max 0.01 ppm max 1 ppb max --
Copper (Cu) 0.1 ppm max 10 ppb max 0.01 ppm max 1 ppb max 100 ppt max
Gallium (Ga) -- 10 ppb max 0.01 ppm max 1 ppb max --
Germanium (Ge) -- 10 ppb max 0.01 ppm max 1 ppb max --
Gold (Au) 0.3 ppm max 5 ppb max 0.02 ppm max 1 ppb max --
Indium (In) -- -- 0.01 ppm max -- --
Iron (Fe) 0.2 ppm max 10 ppb max 0.05 ppm max 1 ppb max 100 ppt max
Lead (Pb) 0.3 ppm max 10 ppb max 0.01 ppm max 1 ppb max 100 ppt max
Lithium (Li) -- 10 ppb max 0.01 ppm max 1 ppb max --