Background Statement for SEMI Draft Document 4499A REVISION OF SEMI C SPECIFICATIONS AND GUIDELINES FOR HYDROCHLORIC ACID

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1 Background Statement for SEMI Draft Document 4499A REVISION OF SEMI C SPECIFICATIONS AND GUIDELINES FOR HYDROCHLORIC ACID Note: This background statement is not part of the balloted item. It is provided solely to assist the recipient in reaching an informed decision based on the rationale of the activity that preceded the creation of this document. Note: Recipients of this document are invited to submit, with their comments, notification of any relevant patented technology or copyrighted items of which they are aware and to provide supporting documentation. In this context, patented technology is defined as technology for which a patent has issued or has been applied for. In the latter case, only publicly available information on the contents of the patent application is to be provided. SEMI C was due for 5 year review. This standard was reviewed by the Analytical Methods TF. The changes were made to bring up to current SEMI guidelines. This letter ballot will be reviewed by the Analytical Methods Task Force and adjudicated by the Liquid Chemicals Committee at their meetings in Dallas, TX, during the week of 7 April, Note: Additions are indicated by underline and deletions are indicated by strikethrough.

2 SEMI Draft Document 4499A REVISION OF SEMI C , SPECIFICATIONS AND GUIDELINES FOR HYDROCHLORIC 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 by letter ballot dated October 17, Initially available at February 2001; to be published March This document replaces SEMI C1.7, C7.2, C8.2, C11.6, and C12.2 in their entirety. Originally published in 1978, 1990, 1992, 1996, and 1995 respectively; previously published June Purpose 1.1 The purpose of this document is to standardize requirements for hydrochloric 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 hydrochloric 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 hydrochloric acid used in the semiconductor industry. NOTICE: 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 or other limitations prior to use. 2.2 The VLSI grade purity level is typically required by semiconductor devices with geometries of microns. 2.3 These specifications and guidelines do not purport to address safety issues, if any, associated with their use. It is the responsibility of the users of these specifications and guidelines 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 and Documents 4.1 SEMI Standards SEMI C1 Specifications for ReagentsGuide for the Analysis of Liquid Chemicals 4.2 ASTM Standards 1 ASTM D5127 Standard Guide for Ultra Pure Water Used in the Electronics and Semiconductor Industry NOTE 1:NOTICE: Unless otherwise indicated, As listed or revised, all documents cited shall be the latest published versionscations of adopted standards. 5 Terminology 5.1 None. 6 Physical Property (for information only) Chemical Formula HCl CAS Number Density at 25 C 1.19 g/ml 1 American Society for Testing and Materials, 100 Barr Harbor Drive, West Conshohocken, Pennsylvania , USA. Telephone: , Fax: Website: Page 1 Doc. 4499A SEMI

3 7 Requirements 7.1 The requirements for hydrochloric acid for Grades 1 and 2, VLSI Grade, and Tiers B and C are listed in Table 1. 8 Grade 1 Procedures NOTE 21: Each laboratory is responsible for verifying the validity of the method within its own operation. 8.1 Assay Accurately weigh a glass-stoppered conical flask containing about 30 ml of water. Deliver from a pipet about 3 ml of sample near the water surface, stopper immediately, and reweigh. Dilute to about 50 ml with water, add methyl orange indicator solution, and titrate with standardized 1 N sodium hydroxide to a red-to-yellow color change. %Assay = ml N of NaOH 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 Extractable Organic Substances Cool 110 ml of sample in an ice bath. Add 5 ml of 2,2,4-trimethylpentane and 100 ml of water to each of two 250 ml separatory funnels. To a third funnel add 100 ml of water and 5 ml of the standard (see below). To the first funnel add 100 ml of the cooled sample, and 100 ml of water to each of the remaining two. Stopper, shake well, and allow the layers to separate. Inject 1.0 µl of each of the 2,2,4- trimethylpentane extracts into a gas chromatograph with a flame ionization detector. The following conditions have been found to be satisfactory: Column 20% Carbowax 20 M on Chromosorb P (80/100), 3 m 3 mm stainless steel or glass; injection port at 280 C with glass insert; column temperature initially 65 C, programmed at 6 C/min up to 140 C; carrier gas nitrogen at 40 ml/min; signal adjusted to give an 80% full-scale deflection; and preferably, electronic integration of peak areas. For DDT: Column 5% silicone gum SESE-30 on Chromosorb W (60/80), mm, injection port as above; column temperature isothermal at 205 C; carrier gas nitrogen at 75 ml/min, and preferably, electronic integration of peak areas. The order of elution is 2,2,4- trimethylpentane, carbon tetrachloride, benzene, chloroform, 2,2,4-trimethylpentane impurity, 1,2-dichloroethane, chlorobenzene, and dichloro-benzene. The total area under the impurity peaks from the sample should be no greater than that from the blank (extract from second funnel) by more than one-half the total area under the peaks from the standard (third funnel), also corrected for the blank Standard Use a syringe to add the volumes of liquid listed in Table 2 into 300 ml of 2,2,4- trimethylpentane. Add 25 mg of DDT to the solution. Dilute to 500 ml with 2,2,4-trimethylpentane. The 2,2,4- trimethylpentane used for both the standard and the analysis should be free from impurities that interfere with the chromatographic analysis. 8.4 Free Halogen (as Cl 2 ) Mix 100 ml of sample and 100 ml of freshly boiled water and cool. Add 0.1 ml of 2% potassium iodide reagent solution and 1 ml of carbon disulfide, and mix. The carbon disulfide should not acquire a pink color in one-half minute. 8.5 Phosphate To 170 ml (200 g) of sample, add 10 ml of sodium carbonate reagent solution (SEMI C1) and evaporate to dryness on a steam bath 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 of p-(methylamino)phenol 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 like the sample. 8.6 Sulfate To ml (100 g) of sample, add 10 ml of sodium carbonate reagent solution and evaporate to dryness in a hood. Dissolve the residue in 10 ml of water and 1 ml of dilute hydrochloric acid (1 + 19); filter, if necessary. Add 1 ml of barium chloride reagent solution, mix, and allow to stand 10 minutes. Any turbidity should be no greater than that produced when 0.05 mg of sulfate ion (SO 4 ) is treated as the sample. 8.7 Sulfite Add 1 ml of 10 percent potassium iodide reagent solution, 5 ml of hydrochloric acid, and 2 ml of starch indicator solution to 400 ml of oxygen-free water. Add 0.01 N iodine until a faint permanent blue color is produced. Add 85 ml of the sample and titrate with 0.01 N iodine to the same endpoint. Not more than 0.20 ml should be required. Page 2 Doc. 4499A SEMI

4 8.8 Arsenic and Antimony (as As) To 168 ml (200 g) of sample in a 400 ml beaker, add 10 ml of nitric acid and 5 ml of sulfuric acid, and evaporate to dense fumes of sulfur trioxide in a hood. Cool, cautiously add 10 ml of water, and again evaporate to dense fumes of sulfur trioxide. Cool and cautiously wash into a generator flask with water to make a volume of 35 ml. Proceed as described in the General Method for Arsenic (and Antimony) under in SEMI C1, Section 3.4.5, starting with tile the 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 mg of arsenic (As). 8.9 Trace Metal Analysis 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), gold (Au), iron (Fe), lead (Pb), magnesium (Mg), manganese (Mn), nickel (Ni), potassium (K), sodium (Na), tin (Sn), titanium (Ti), and zinc (Zn). Alternative methods may be used as long as appropriate method validation as per SEMI C1 can be demonstrated. studies demonstrate recovery between % of a known sample spike for half of the value of each specified item Special Reagents Nitric Acid, Ultra Pure Use nitric acid specified for ultra low metal ion content % Nitric Acid Solution Dilute 20 ml of ultra pure nitric acid to 1 L using water meeting the criteria for Type E1.1 in ASTM D Sample Preparation In a clean environment, place 250 ml of sample in a PTFE evaporating dish. Slowly evaporate on a hot plate, avoiding loss of sample by effervescence or spattering until approximately 2 ml of liquid remains. Note: Evaporation typically requires 2 1/2 to 4 hours. Cool. Transfer quantitatively to a 50 ml volumetric flask using 2% nitric acid for rinsing and dilution to volume. Run a reagent blank Analysis Using the acid sample and reagent blank, analyze group 1 elements by flame atomic absorption spectroscopy and all other elements by plasma emission spectroscopy. 9 Grade 2 Procedures NOTE 2: 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) Free Halogen Phosphate Sulfate Sulfite 9.2 Trace Metals Analysis 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), cadmium (Cd),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), and zinc (Zn), and zirconium (Zr). Alternative methods may be used as long as appropriate method validation as per SEMI C1 can be demonstrated. studies demonstrate a recovery between % of a known sample spike for half of the value of each specified element Special Reagents Page 3 Doc. 4499A SEMI

5 Hydrochloric Acid, Ultrapure Use hydrochloric acid specified for low metal ion content % Hydrochloric Acid Solution Dilute 20 g of ultrapure hydrochloric acid to 200 g using water meeting the criteria for Type E1.1 in ASTM D Nitric Acid, Ultrapure Use nitric acid specified for low metal ion content % Nitric Acid Solution Dilute 10 ml of ultrapure nitric acid to 1 L using water meeting the criteria for Type E1.1 in ASTM D 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 Rhodium Internal Standard Make up the internal standard solution to a concentration of 20 µg/ml (ppm) from the appropriate concentrated standard rhodium solution Sample Preparation In a clean environment, place 2.00 g of sample into a tared FEP bottle (30 ml), dilute with attainable Type E1.1 water to a final weight of 20.0 g. Add 20 µl of the rhodium internal standard solution. Run a reagent blank Vanadium In a clean environment, place 20.0 g of sample into a clean PTFE 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 20 g with 1% nitric acid, add 20 µl of the rhodium internal standard, mix well. Run a reagent blank Analysis 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 3.7% hydrochloric acid solution and the rhodium internal standard except for the analysis of vanadium which is performed using 1% nitric acid as the matrix. All standards must contain 10 ng/g of rhodium as the internal standard. 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. 12 Grade 5 Procedures 12.1 This section does not apply to this chemical. 13 VLSI Grade Procedures 12.2 Specific procedures for this grade do not exist. Refer to Sections 8 and 9 for available procedures Tier A Procedures This section does not apply to this chemical Tier B Procedures 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 supplier. The Liquid Process Chemicals Committee considers a test method to be valid only if there is a documented recovery study showing a recovery of %. Recovery is for a known sample spike at 50% of the specified levelmethod validation according to SEMI C1 can be demonstrated. Page 4 Doc. 4499A SEMI

6 1615 Tier C Procedures 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 Process Liquid Chemicals Committee considers a test method to be valid only if method validation according to SEMI C1 can be demonstratedthere is a documented recovery study showing a recovery of %. Recovery is for a known sample spike at 50% of the specified level Tier D Procedures This section does not apply to this chemical. Table 1 Impurity Limits and Other Requirements for Hydrochloric Acid Previous SEMI Reference # C C C C C Grade 1 Grade 2 VLSI Grade Tier B Tier C (Specification) (Specification) (Guideline) (Guideline) (Guideline) Assay (HCl) % % 36 38% % % Color (APHA) 10 max 10 max 10 max 10 max 10 max Extractable Organic Substances 5 ppm max ppb max -- Residue after Ignition (as SO 4 ) ppm max Free Halogen (as Cl 2 ) To pass test To pass test ppb max 500 ppb max Free Chlorine (Cl 2 ) ppm max Bromide (Br) ppm max Phosphate (PO 4 ) 0.05 ppm max 50 ppb max 0.05 ppm max 50 ppb max 50 ppb max Sulfate (SO 4 ) 0.5 ppm max 500 ppb max 0.5 ppm max 100 ppb max 30 ppb max Sulfite (SO 3 ) 0.8 ppm max 800 ppb max 0.7 ppm max 100 ppb max 100 ppb max Aluminum (Al) 0.3 ppm max 10 ppb max 0.05 ppm max 1 ppb max 100 ppt max Antimony (Sb) -- 5 ppb max ppm max --1 ppb max 100 ppt max Arsenic (As) ppb max ppm max --1 ppb max 100 ppt max Arsenic and Antimony (as As) ppm max ppb max -- Barium (Ba) ppb max 0.05 ppm max 1 ppb max 100 ppt max Beryllium (Be) ppb max 0.02 ppm max 1 ppb max -- Bismuth (Bi) ppb max 0.02 ppm max 1 ppb max -- Boron (B) 0.1 ppm max 10 ppb max 0.02 ppm max 1 ppb max 100 ppt max Cadmium (Cd) ppb max ppm max 1 ppb max ppt max Calcium (Ca) 0.3 ppm max 10 ppb max 0.2 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) ppb max 0.01 ppm max 1 ppb max 100 ppt max Copper (Cu) 0.1 ppm max 10 ppb max 0.01 ppm max 1 ppb max 100 ppt max Gallium (Ga) ppb max 0.02 ppm max 1 ppb max -- Germanium (Ge) ppb max -- 1 ppb max -- Gold (Au) 0.3 ppm max 5 ppb max 0.02 ppm max 1 ppb max -- Indium (In) ppm max Iron (Fe) 0.2 ppm max 10 ppb max 0.1 ppm max 1 ppb max 100 ppt max Lead (Pb) 0.1 ppm max 10 ppb max 0.02 ppm max 1 ppb max 100 ppt max Lithium (Li) ppb max 0.02 ppm max 1 ppb max ppt max Magnesium (Mg) 0.3 ppm max 10 ppb max 0.05 ppm max 1 ppb max 100 ppt max Manganese (Mn) 0.3 ppm max 10 ppb max 0.01 ppm max 1 ppb max 100 ppt max Mercury (Hg) ppm max Molybdenum (Mo) ppb max 0.02 ppm max 1 ppb max -- Page 5 Doc. 4499A SEMI

7 Previous SEMI Reference # C C C C C Grade 1 Grade 2 VLSI Grade Tier B Tier C (Specification) (Specification) (Guideline) (Guideline) (Guideline) Nickel (Ni) 0.1 ppm max 10 ppb max 0.01 ppm max 1 ppb max 100 ppt max Niobium (Nb) ppb max -- 1 ppb max -- Platinum (Pt) ppm max Potassium (K) 0.3 ppm max 10 ppb max 0.05 ppm max 1 ppb max 100 ppt max Silicon (Si) ppb max -- Silver (Ag) -- 5 ppb max 0.02 ppm max 1 ppb max -- Sodium (Na) 0.3 ppm max 10 ppb max 0.1 ppm max 1 ppb max 100 ppt max Strontium (Sr) ppb max 0.02 ppm max 1 ppb max -- Tantalum (Ta) ppb max -- 1 ppb max 100 ppt max Thallium (Tl) ppb max 0.02 ppm max 1 ppb max -- Tin (Sn) 0.3 ppm max 10 ppb max 0.02 ppm max 1 ppb max 100 ppt max Titanium (Ti) 0.3 ppm max 10 ppb max 0.05 ppm max 1 ppb max 100 ppt max Vanadium (V) ppb max 0.02 ppm max 1 ppb max ppt max Zinc (Zn) 0.3 ppm max 10 ppb max 0.05 ppm max 1 ppb max 100 ppt max Zirconium (Zr) ppb max 0.02 ppm max 1 ppb max -- Particles in bottles (size, #/ml) (See NOTE 1.) 1.0 μm, 25 max (See NOTE 1.) 0.5 μm, 25 max 0.5 μm, 250 max (See NOTE 1.) 0.5 μm, 10 max 0.2 μm, TBD (See NOTE 1.) NOTE 1: Due to the limitations of current particle counters, particle size and number are to be agreed upon between supplier and user. See SEMI C1, Section 3.9 Calibration and Measurement Method for Particles in Liquids. Table 2 Composition of Standard Substance Amount in 500 ml of 2,2,4-trimethylpentane solution μl mg Concentration in ppm for 5 ml of standard in 100 ml (120 g) of HCl Benzene Chlorobenzene ,2-Dichloroethane Chloroform DDT (see NOTE 1) Total 9.0 Allowance for CCl Total 10.0 NOTE 1: 1,1,1-Trichloro-2,2-bis (p-chlorophenyl) ethane, dichlorodiphenyltrichloroethane. NOTICE: SEMI makes no warranties or representations as to the suitability of the specifications and guidelines set forth herein for any particular application. The determination of the suitability of the specifications and guidelines 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 specifications and guidelines are subject to change without notice. The user s attention is called to the possibility that compliance with these specifications and guidelines may require use of copyrighted material or of an invention covered by patent rights. By publication of these specifications and guidelines, SEMI takes no position respecting the validity of any patent rights or copyrights asserted in connection with any item mentioned in these specifications and guidelines. Users of these specifications and guidelines 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. Page 6 Doc. 4499A SEMI