SEMI C3.39-0999 STANDARD FOR NITROGEN TRIFLUORIDE (NF3).pdf.pdf

SEMI C3.39-0999 SEMI 1989, 19991 SEMI C3.39-0999 STANDARD FOR NITROGEN TRIFLUORIDE (NF3) This standard was technically approved by the Global Gases Committee and is the direct responsibility of the North American Gases Committee. Current edition approved by the North American Regional Standards Committee on October 18, 1998.Initially available on SEMI OnLine August 1999; to be published September 1999. Originally published in 1989; previously published in 1996. 1 Description 1.1 Nitrogen trifluoride is a toxic, odorless, colorless, nonflammable gas. It is a strong oxidizer and supports combustion. 2 Specifications 2.1 QUALITY: 99.98% ImpuritiesMaximum Acceptable Level (ppm) (see NOTE 1) Carbon Dioxide (CO2)10 Carbon Monoxide (CO)10 Carbon Tetrafluoride (CF4)100 Nitrogen (N2)10 Nitrous Oxide (N2O)10 Argon/Oxygen10 Sulfur Hexafluoride (SF6)10 Water (H2O) (v/v)1 TOTAL IMPURITIES161 (see NOTE 1) NOTE 1: An analysis of significant figures has not been considered. The number of significant figures will be based on analytical accuracy and the precision of the provided procedure. 3 Chemical Specification Hydrolyzable Fluorides as HF1 ppm 4 Physical Constants (for information only) Metric UnitsUS Units Molecular weight71.0071.00 Density of gas at 21.1C (70F) and 1 atm 2.94 kg/m30.1838 lb./ft.3 5 Analytical Procedures 5.1 Carbon Tetrafluoride This procedure is for the determinationofcarbontetrafluorideinnitrogen trifluoride using a gas chromatograph with a thermal conductivity detector. (See Figure 1 and Note 1.) 5.1.1 Detection Limit 1.0 ppm. 5.1.2 Instrument Parameters 5.1.2.1 Column: Super Q (80/100 mesh), 4.9 m (16 ft.) by 1.75 mm (1/16 in.) ID, 3.2 mm (1/8 in.) OD ss or equivalent. 5.1.2.2 Carrier Flow: 19 mL/min helium. 5.1.2.3 Sample Volume: 0.1 mL. 5.1.2.4 Temperatures: Detector100C Oven42C Gas sampling valve42C 5.1.2.5 Valve material: Nitronic-60 or equivalent. 5.1.3Calibration Standard 100 ppmcarbon tetrafluoride, balance helium. 5.1.4 Operating Procedure 5.1.4.1 Inject the calibration standard into the column using a gas sampling valve. Record retention time and peak area. 5.1.4.2 Inject nitrogen trifluoride sample to be tested in the same manner as the calibration standard. Record the retention times and peak areas. 5.1.4.3 Repeat 5.1.4.1. 5.1.4.4Comparetheaveragepeakareaofthe calibration standard to that of the nitrogen trifluoride sample being tested. Calculate the concentration of carbon tetrafluoride, using the formula below. The result may not exceed the specification in Section 2 of this Standard. Sample Peak Area Standard Peak Area Concentration of Standard = Concentration of Sample 5.2Carbon Dioxide, Nitrous Oxide,andSulfur Hexafluoride This procedure is for the determination ofcarbondioxide,nitrousoxide,andsulfur hexafluorideinnitrogentrifluorideusingagas chromatograph with a thermal conductivity detector. (See Figure 1.) 5.2.1 Detection Limit 1.0 ppm for carbon dioxide, nitrous oxide, and sulfur hexafluoride. 5.2.2 Instrument Parameters 5.2.2.1 Column: Super Q (80/100 mesh), 4.9 m (16 ft.) by 1.75 mm (1/16 in.) ID, 3.2 mm (1/8 in.) OD ss or equivalent. SEMI C3.39-0999 SEMI 1989, 19992 5.2.2.2 Carrier Flow: 19 mL/min helium. 5.2.2.3 Sample Volume: 1.0 mL. 5.2.2.4 Temperatures: Detector100C Oven42C Gas sampling valve42C 5.2.2.5 Valve Material: Nitronic-60 or equivalent. 5.2.3 Calibration Standard 10 ppm carbon dioxide, 10 ppm nitrous oxide, 10 ppm sulfur hexafluoride, balance helium. 5.2.4 Operating Procedure 5.2.4.1 Inject the calibration standard into the column using a gas sampling valve. Record the retention times and peak areas. The order of elution is carbon dioxide, nitrous oxide, sulfur hexafluoride. (See Figure 1 for valve configuration.) 5.2.4.2 Inject the sample to be tested in the same manner as the calibration standard. Record the retention times and peak areas. 5.2.4.3 Repeat 5.4.2.1. 5.2.4.4Comparetheaveragepeakareaofthe calibration standard to that of the nitrogen trifluoride sample being tested. Calculate the concentration of each impurity using the formula below. The results may not exceed the specifications in Section 2 of this Standard. Sample Peak Area Standard Peak Area Concentration of Standard = Concentration of Sample 5.3 Carbon Monoxide This procedure is for the determinationofcarbonmonoxideinnitrogen trifluoride using a gas chromatograph with a methanizer and a flame ionization detector. (See Figure 1 and Note 2.) 5.3.1 Detection Limit 0.1 ppm. 5.3.2 Instrument Parameters 5.3.2.1 Column: Carbosphere (80/100 mesh), 0.74 m (2.4 ft) by 1.75 mm (1/16 in) ID, 3.2 mm (1/8 in) OD ss or equivalent. 5.3.2.2 Carrier Flow: 25 mL/min helium. 5.3.2.3 Sample Volume: 0.5 mL. 5.3.2.4 Fuel gases: Hydrogen:Zero grade or better hydrogen at a flow rate of 45 mL/min is added to the carrier gas between the column outlet and the methanizer inlet. Air:Zero grade or better air is used at a flow rate of 300 mL/min. 5.3.2.5 Temperatures: Detector150C Oven42C Methanizer340C Gas sampling valve70C 5.