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Background Statement for SEMI Draft Document #5356C

REVISION OF SEMI C51-0706, SPECIFICATIONS AND GUIDELINES FOR XYLENES with title change to: SPECIFICATIONS AND GUIDELINESFOR XYLENES

Notice: 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.

Notice: 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.

Background

SEMI C51 is due for 5-year review. As a result of the review process, this ballot proposes minor changes for consistency with other SEMI Standards on liquid chemicals. These changes are marked by strikethrough for deletions and underlines for additions.

Review and Adjudication Information

Task Force Review / Committee Adjudication
Group: / Analytical Methods TF / N.A. Liquid Chemicals Committee
Date: / Tuesday, July 9, 2013 / Tuesday, July 9, 2013
Time & Timezone: / 10:00 AM to 12:00 PM Noon (PST) / 1:00 PM to 4:00 PM (PST)
Location: / San Francisco Marriott Marquis Hotel in conjunction with SEMICON West 2013 / San Francisco Marriott Marquis Hotel in conjunction with SEMICON West 2013
City, State/Country: / San Francisco, CA/USA / San Francisco, CA/USA
Leader(s): / Frank Flowers () / Frank Flowers ()
Frank Parker ()
Standards Staff: / Michael Tran (SEMI N.A.)
408.943.7019
/ Michael Tran (SEMI N.A.)
408.943.7019

This meeting’s details are subject to change, and additional review sessions may be scheduled if necessary. Contact the task force leaders or Standards staff for confirmation.

Telephone and web information will be distributed to interested parties as the meeting date approaches. If you will not be able to attend these meetings in person but would like to participate by telephone/web, please contact Standards staff.

Notice:Additions are indicated by underline and deletions are indicated by strikethrough.

SEMI Draft Document #5356C

REVISION TO SEMI C51-0706, SPECIFICATIONS AND GUIDELINES FOR XYLENES with title change to: SPECIFICATIONS AND GUIDELINESFOR XYLENES

1 Purpose

1.1 The purpose of this document is to standardize requirements for xylenes used in the semiconductor industry and to document testing procedures to support thisose standards. Test methods have been shown to give statistically valid results.

2 Scope

2.1 The scope of this document is aall grades of xylenes used in the semiconductor industry.

2.2 This material is a mixture of ortho, meta, and para isomers and ethyl benzene. Xylene (o-, m-, and p- isomers and ethyl benzene) 99.0% min and Ethyl benzene 18% max.

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.

NOTICE: SEMI Standards and Safety Guidelines do not purport to address all safety issues associated with their use. It is the responsibility of the users of the Documents to establish appropriate safety and health practices, and determine the applicability of regulatory or other limitations prior to use.

3 Limitations

3.1 None.

4 Referenced Standards and Documents

4.1 SEMI Standards

SEMI C1 — Guide 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

NOTICE: Unless otherwise indicated, all documents cited shall be the latest published versions.

5 Terminology

5.1 None.

6 Properties

6.1 Density at 25°C 0.86 g/ml

6.2 Boiling Range 136–144°C

Table 1Properties for Xylenes

Chemical Formula / C8H10
Molecular Weight / 106.16
CAS # / 1330-20-7
Density at 25°C / 0.86 g/ml
Boiling Range / 136–144°C

7 Requirements

7.1 The requirements for xylenes for Grade 1 are listed in Table 12.

8 Grade 1 Procedures

8.1 Assay — Analyze the sample by gas chromatography (see SEMI C1, ¶ 7.2 ‘Assay by Wide Bore Column Gas Chromatography’). The parameters cited have given satisfactory results.

  • Column: 30 meter × 530 micron I.D. fused silica capillary, coated with 5 micron film of DB-Wax or equivalent (100% methyl silicone which has been surface bonded and cross linked).
  • Column Temperature: 40°C isothermal for 5 minutes, then programmed to 200°C at 10°C/min.
  • Injector Temperature: 175°C: Detector: Thermal Conductivity or Flame Ionization, Detector Temperature:250°C.
  • Sample size: 0.2 µL splitless: Carrier Gas: Helium at 3 mL/min:
  • Approximate Retention Times (min): Toluene – 14.4, Ethyl benzene – 17.0, p-xylene – 16.9, m-xylene – 17.2, o-xylene – 17.8.
  • 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.
  • Acidity — To 25 mL of water in a glass-stoppered flask, add 10 mL of sample and 0.1 mL of phenolphthalein indicator solution (see SEMI C1). Add 0.01N sodium hydroxide until a slight pink color persists after shaking for one-half minute. Add 38 mL (33 g) of the sample, mix well, and titrate with 0.01N sodium hydroxide until the pink color is reproduced. Not more than 1.0 mL of the sodium hydroxide solution should be required.
  • Residue after Evaporation — Evaporate 232 mL (200 g) of sample to dryness. Dry at 105°C for 30 minutes, cool in a desiccator, and weigh (see SEMI C1, ¶ 4.15 ‘Residue after Evaporation’).
  • Water — Add 25 mL of methanol to a dry titration flask and add Karl Fischer (KF) reagent to a visually or electrometrically determined endpoint that persists for 30 seconds. Add 23 mL (20 g) of sample, taking care to protect the sample and contents of the flask from moisture. Stir vigorously and titrate with Karl Fischer reagent to the same endpoint.

(1)

8.6 Chloride — To a 100 mL separatory funnel, add 12 mL (10 g) of sample and 40 mL of water. Shake well for 30 seconds and allow the two layers to separate. Discard the sample (upper) layer. To a 20 mL portion of the water layer add 1 mL of nitric acid and 1 mL of silver nitrate reagent solution (see SEMI C1). Any turbidity producedshouldshall be no greater than that of a standard containing 0.015 mg of chloride ion (Cl) in an equal volume of solution and the amounts of reagents used.

8.7 Phosphate — To 12 mL (10 g) of sample, add 10 mL of sodium carbonate reagent solution (see 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 (see SEMI C1) and 1 mL of p-(methylamino)phenol sulfate reagent solution (see SEMI C1). Allow to stand at room temperature for 2 hours. Any blue color produced shouldshall be no greater than that produced when 0.01 mg of phosphate ion (PO4) is treated like the sample.

8.8 Arsenic and Antimony (as As) — Evaporate 116 mL (100 g) of sample in a 250 mL beaker to a small volume in a hood. Add 50 mL of water and again evaporate to a small volume. Repeat the evaporation three times with water additions. Do not allow to go to dryness. Add 5 mL of nitric acid and 5 mL of sulfuric acid and evaporate to dense fumes of sulfur trioxide. 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 SEMI C1, § 7.6 ‘Trace Arsenic (and Antimony) Determination’, starting with the sentence that begins, “Swirl the flask...”. Any red color in the silver diethyldithiocarbamate solution of the sample shouldshall be no greater than that of the standard containing 0.001 mg of arsenic (As).

8.9 Trace MetalAnalysis

8.9.1 Boron — To 116 mL (100 g) of sample, add 0.10 mL of 10% sodium hydroxide, and evaporate to dryness in a nitrogen atmosphere using a covered chamber such as a Thiers assembly or equivalent (see SEMI C1). Dissolve the residue with 2mL of water and 0.10 mL of hydrochloric acid. Transfer to a test tube, cool in an ice bath, and add 10 mL of sulfuric acid. Add 10 mL of carminic acid solution (¶ 8.9.1.1) and remove from the ice bath. Allow to stand for 45 minutes. Prepare a standard containing 0.01 mg of boron treated exactly as the sample (¶ 8.9.1.2). Run a complete blank determination on 2 mL of water. Measure the absorbances of the sample and standard against the blank at 585nm using 5 cm cells. The absorbance of the sample solution shouldshall be no greater than that of the standard.

8.9.1.1 Carminic Acid Solution — Dissolve 0.05 g of carminic acid in 100 mL of sulfuric acid and shake until dissolution is complete.

8.9.1.2 Boron Standard Solution — Dissolve 0.572 g of boric acid in water in a 1000 mL volumetric flask. Dilute to the mark with water. Dilute 10.0 mL of this solution with water to the mark in a 1000 mL volumetric flask (1mL= 0.001 mg boron).

8.10 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), antimony (Sb), arsenic (As), barium, (Ba),boron (B), cadmium (Cd), calcium (Ca), chromium (Cr), copper (Cu), iron (Fe), lead (Pb), lithium (Li), magnesium (Mg), manganese (Mn), nickel (Ni), potassium (K), sodium (Na), tin (Sn), titanium (Ti),vanadium (V), and zinc (Zn). Alternate methods may be used as long as they are validated for each metal according to SEMI C1. , § 6 ‘Method Validation’.

8.10.1 SpecialReagents

8.10.1.1 Hydrochloric Acid, Ultra Pure — Use concentrated hydrochloric acid with metal ion content less than 1 ppb for each element of interestspecified for ultra low metal ion content.

8.10.1.2 2% (v/v) Hydrochloric Acid Solution — Dilute 20 mL of ultra pure 12 M hydrochloric acid to 1 L using water meeting the criteria for Type E1.1 in ASTM D5127 in regard to metallic impurities.

8.10.2 SamplePreparation

8.10.2.1 Tin — To a 100 g (116 mL) sample in a PTFE dish add 1 mL of 1% oxalic acid solution. Slowly evaporate to about 1 mL. Dissolve the residue in 10% hydrochloric acid and transfer to a 10 mL volumetric flask using 10% hydrochloric acid. Analyze by inductively coupled plasma optical emission spectrometry (ICP-OES) using matrix-matched standards.

8.10.2.2 All Other Elements — In a clean environment, place 250 g of sample in a PTFE dish. Slowly evaporate on a hot plate avoiding loss of sample by effervescence or spattering until approximately 1 mL of liquid remains. Take up liquid and all visible residue (from walls of dish) with 1 mL ultra pure, 12 M hydrochloric acid (see ¶ 8.10.1.1) and continue heating until approximately 0.5 mL of liquid remains. No undissolved particulate matter shouldshall be observed. Otherwise repeat the addition of hydrochloric acid until all particulate matter is dissolved. Transfer quantitatively to a 50 mL volumetric flask using 2% (v/v) hydrochloric acid (see ¶ 8.10.1.2) and adjust liquid level to mark. Prepare a reagent blank using the same reagents and in the same manner as for the sample concentration.

8.10.3 Analysis

8.10.3.1 Using the prepared sample and reagent blank, analyze group I elements potassium (K) and sodium (Na) by atomic absorption spectroscopy and all other elements by ICP-OES. If necessary, apply a reagent blank correction to the final determined value of the sample.

9 Grade 2 Procedures

9.1 This section does not apply to this chemical.

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 Tier A Procedures

13.1 This section does not apply to this chemical.

14 Tier B Procedures

14.1 This section does not apply to this chemical.

15 Tier C Procedures

15.1 This section does not apply to this chemical.

16 Tier D Procedures

16.1 This section does not apply to this chemical.

Table 2Table 1 Impurity Limits and Other Requirements for Xylenes
Previous SEMI Reference # / C1.21-92
Grade 1
(Specification)
Color (APHA) / 10 max
Acidity / 0.3 eq/g max
Residue after Evaporation / 5 ppm max
Water (H2O) / 0.02% max
Chloride (Cl) / 3 ppm max
Phosphate (PO4) / 1 ppm max
Arsenic and Antimony (as As) / 0.01 ppm max
Aluminum (Al) / 0.1 ppm max
Antimony (Sb) / --
Arsenic (As) / 0.01 ppm max--
Barium (Ba) / --
Boron (B) / 0.1 ppm max
Cadmium (Cd) / --
Calcium (Ca) / 0.1 ppm max
Chromium (Cr) / 0.1 ppm max
Copper (Cu) / 0.1 ppm max
Iron (Fe) / 0.1 ppm max
Lead (Pb) / 0.1 ppm max
Lithium (Li) / --
Magnesium (Mg) / 0.1 ppm max
Manganese (Mn) / 0.1 ppm max
Nickel (Ni) / 0.1 ppm max
Potassium (K) / 0.1 ppm max
Sodium (Na) / 0.1 ppm max
Tin (Sn) / 0.1 ppm max
Titanium (Ti) / --
Vanadium (V) / --
Zinc (Zn) / 0.1 ppm max
Particles in bottles:
size, #/mL / (See Note #1#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, §7.14 ‘Calibration and Measurement Method for Particles in Liquids’).

NOTICE:Semiconductor Equipment and Materials International (SEMI) makes no warranties or representations as to the suitability of the Standards and Safety Guidelines set forth herein for any particular application. The determination of the suitability of the Standard or Safety Guideline 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 or equipment mentioned herein. Standards and Safety Guidelines are subject to change without notice.

By publication of this Standard or Safety Guideline, SEMI takes no position respecting the validity of any patent rights or copyrights asserted in connection with any items mentioned in this Standard or Safety Guideline. Users of this Standard or Safety Guideline 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.

This is a Draft Document of the SEMI International Standards program. No material on this page is to be construed as an official or adopted Standard or Safety Guideline. Permission is granted to reproduce and/or distribute this document, in whole or in part, only within the scope of SEMI International Standards committee (document development) activity. All other reproduction and/or distribution without the prior written consent of SEMI is prohibited.

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