SEMI C51-0699 SPECIFICATION FOR XYLENES.pdf.pdf

XYLENESSEMI C51-0699 SEMI 1978, 19991 SEMI C51-0699 SPECIFICATION FOR XYLENES This specification was technically approved by the Global Process Chemicals Committee and is the direct responsibility of the North American Process Chemicals Committee. Current edition approved by the North American Regional Standards Committee on April 23, 1999. Initially available on SEMI OnLine May 1999; to be published June 1999.This document replaces SEMI C1.21 in its entirety.Originally published in 1978. 1 Purpose 1.1 The purpose of this document is to standardize requirements for xylenes used in the semiconductor industry andtestingprocedurestosupportthose standards. Test methods have been shown to give statistically valid results. This document also provides guidelines for grades of xylenes 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 xylenes used in the semiconductor industry. 2.2 This material is a mixture of ortho, meta, and para isomers and ethylbenzene. Xylene (o-, m-, and p- iso- mers and ethylbenzene) 99.0% min and Ethylbenzene 18% max. 3 Limitations 3.1 None. 4 Referenced Documents SEMI C1 Specifications for Reagents 5 Terminology 5.1 None. 6 Physical Property (for information only) Density at 25C0.86 g/mL Boiling Range136 - 144C 7 Requirements 7.1 The requirements for xylenes for Grade 1 are listed in Table 1. 8 Grade 1 Procedures 8.1 Assay Assay the sample by gas chromatography (see SEMI C1, Section 3.1, Guidelines for Assay by Wide Bore 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-1 or equivalent (100% methyl Silicone which has been surface bonded and cross linked). Column Temperature: 40C isothermal for 5 minutes, then programmed to 200C at 10C/min. Injector Temperature:175C Detector Temperature:250C Sample Size:0.2 L splitless Carrier Gas:Helium at 3 mL/min Detector:Thermal Conductivity or Flame Ionization Approximate Retention Times (min): Toulene14.4 Ethylbenzene17.0 p-xylene16.9 m-xylene17.2 o-xylene17.8 8.1.1Measure the areas under all peaks by any convenient means and calulate the concentration of all components in area percent (see SEMI C.1, Section 3.11, Guidelines for Assay by Wide Bore Column Gas Chromatography). 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 Acidity To 25 mL of water in a glass-stoppered flask,add10mLofsampleand0.1mLof phenolphthalein indicator solution. Add 0.01 N 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 0.01 N sodium hydroxide until the pink color is reproduced. Not more than 1.0 mL of the sodium hydroxide solution should be required. 8.4 Residue After Evaporation Evaporate 232 mL (200 g) of sample to dryness. Dry at 105C for 30 minutes, cool in a desiccator, and weigh (see SEMI C1, SEMI C51-0699 SEMI 1978, 1999XYLENES2 Section3.3,DeterminationofResidueAfter Evaporation). 8.5 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. % WaterH2O()= mL KF reagent KF factor (g H2O/mL) 100 Weight of sample (g) 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. Any turbidity produced should 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 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 sulfate reagent solution. Allow to stand at room temperature for 2 hours. Any blue color should be no greater than that produced when 0.01 mg of phosphate ion (PO4) is treated as 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 s