semi合集-English.pdf - 第6728页
SULFURIC ACID SEMI C44-0301 © SEMI 1978, 20 01 1 SEMI C44-0301 SPECIFICA TIONS AND GUIDELINES FOR SULFURIC A CID These specific ations and gui delines were technica lly approv ed by the Global Proc ess Chem ic als Commit…
SEMI C43-0699 © SEMI 19993
15 Tier B Procedures
15.1 This section does not apply to this chemical.
16 Tier C Procedures
16.1 This section does not apply to this chemical.
17 Tier D Procedures
17.1 This section does not apply to this chemical.
Table 1 Impurity Limits and Other Requirements for Sodium Hydroxide, 50% Solution
Previous SEMI Reference # --
Grade 1
(Specification)
Assay (NaOH) 50.0 - 52.0%
Ammonium Hydroxide
Precipitate
0.01% max
Insoluble Matter 50 ppm max
Nitrogen Compounds (as N) 5 ppm max
Chloride (Cl) 40 ppm max
Phosphate (PO
4
) 5 ppm max
Sodium Carbonate (Na
2
CO
3
)0.1% max
Sulfate (SO
4
) 10 ppm max
Heavy Metals (as Ag) 10 ppm max
Iron (Fe) 5 ppm max
Nickel (Ni) 5 ppm max
Potassium (K) 0.01% max
NOTICE: These standards do not purport to address
safety issues, if any, associated with their use. It is the
responsibility of the user of these standards to establish
appropriate safety and health practices and determine
the applicability of regulatory limitations prior to use.
SEMI makes no warranties or representations as to the
suitability of the standards set forth herein for any
particular application. The determination of the
suitability of the standard is solely the responsibility of
the user. Users are cautioned to refer to manufacturer’s
instructions, product labels, product data sheets, and
other relevant literature respecting any materials
mentioned herein. These standards are subject to
change without notice.
The user’s attention is called to the possibility that
compliance with this standard may require use of
copyrighted material or of an invention covered by
patent rights. By publication of this standard, SEMI
takes no position respecting the validity of any patent
rights or copyrights asserted in connection with any
item mentioned in this standard. Users of this standard
are expressly advised that determination of any such
patent rights or copyrights, and the risk of infringement
of such rights, are entirely their own responsibility.
Copyright by SEMI® (Semiconductor Equipment and Materials
International), 3081 Zanker Road, San Jose, CA 95134. Reproduction o
f
the contents in whole or in part is forbidden without express written
consent of SEMI.
SULFURIC ACID SEMI C44-0301 © SEMI 1978, 20011
SEMI C44-0301
SPECIFICATIONS AND GUIDELINES FOR SULFURIC ACID
These specifications and guidelines were technically approved by the Global Process Chemicals Committee
and are the direct responsibility of the North American Process Chemicals Committee. Current edition
approved by the North American Regional Standards Committee on October 17, 1999. Initially available at
www.semi.org February 2001; to be published March 2001. This document replaces SEMI C1.16, C7.8,
C8.8, and C11.5 in their entirety. Originally published in 1978, 1990, 1992, and 1994 respectively;
previously published October 2000.
1 Purpose
1.1 The purpose of this document is to standardize
requirements for sulfuric acid used in the
semiconductor industry and testing procedures to
support those standards. Test methods have been shown
to give statistically valid results. This document also
provides guidelines for grades of sulfuric acid for which
a need has been identified. In the case of the guidelines,
the test methods may not have been statistically
validated yet.
2 Scope
2.1 The scope of this document is all grades of sulfuric
acid used in the semiconductor industry.
2.2 The VLSI grade purity level is typically required
by semiconductor devices with geometries of 0.8–1.2
microns.
2.3 This standard does not purport to address safety
issues, if any, associated with its use. It is the
responsibility of the users of this standard to establish
appropriate safety and health practices and determine
the applicability of regulatory limitations prior to use.
3 Limitations
3.1 None.
4 Referenced Standards
4.1 SEMI Standards
SEMI C1 — Specifications for Reagents
4.2 ASTM Standards
1
ASTM D5127 — Standard Guide for Ultra Pure Water
Used in the Electronics and Semiconductor Industry
NOTE 1: As listed or revised, all documents cited shall be the
latest publications of adopted standards.
1 American Society for Testing and Materials, 100 Barr Harbor
Drive, West Conshohocken, Pennsylvania 19428-2959, USA.
Telephone: 610.832.9585, Fax: 610.832.9555. Website:
www.astm.org
5 Terminology
5.1 None.
6 Physical Property (for information only)
Density at 25°C
1.83 g/mL
7 Requirements
7.1 The requirements for sulfuric acid for Grades 1
and 2, VLSI Grade, and Tiers B and C are listed in
Table 1.
8 Grade 1 Procedures
NOTE 2: Each laboratory is responsible for verifying the
validity of the method within its own operation.
8.1 Assay — Accurately weigh 1 mL of sample in a
small glass-stoppered conical flask. Cautiously add 30
mL of water, cool, add 0.1 mL of methyl orange
indicator solution, and titrate with standardized 1.0 N
sodium hydroxide to a red to yellow color change.
%Assay
=
mL
×
N
of NaOH
×
4.904
Weight of sample g()
8.2 Color — Dilute 2.0 mL of platinum-cobalt stock
solution (APHA No. 500) to 100 mL with water.
Compare this standard (APHA No. 10) with 100 mL of
sample in Nessler tubes. View vertically over a white
background. The sample must be no darker than the
standard.
8.3 Chloride — Place 40 mL of water in each of two
beakers. To one, add carefully 27 mL (50 g) of sample
and to the other, 27 mL (50 g) of chloride-free sulfuric
acid and 0.005 mg of chloride ion (Cl). Cool to room
temperature and add 1 mL of nitric acid and 1 mL of
silver nitrate reagent solution. Mix well; if necessary,
make the volume of each solution identical by adding
water. After 10 minutes, measure the turbidity of each
solution using a suitable nephelometer. The turbidity in
the sample should be no greater than the standard.
NOTE 3: Prepare chloride-free sulfuric acid in a hood by
gently fuming sulfuric acid in a crucible or dish for at least 30
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.