Title :
Atmospheric pressure ionization mass spectroscopy for the study of permeation in polymeric tubing
Author :
Ma, Ce ; Haider, Asad M. ; Shadman, Farhang
Author_Institution :
Dept. of Chem. Eng., Arizona Univ., Tucson, AZ, USA
fDate :
11/1/1993 12:00:00 AM
Abstract :
An atmospheric pressure ionization mass spectrometer (APIMS) is used to determine the permeation coefficients for two widely used kinds of polymeric tubing, PF and Kel-F (PCTFE), at 25°C and 75°C. In the experiments, an ultra-high-purity N2 gas flow was maintained through the test tubing. The net impurity uptake by nitrogen due to the permeation of O2, CO2, H2O, and CH4 from surrounding air into the polymeric tubing was measured by APIMS with sub-ppb sensitivities. CH4 had the highest and O2 had the lowest permeation coefficients. Results show that Kel-F was a superior barrier material for all impurities studied. The permeation coefficients for these polymers increased with temperature but did not change significantly with the permeant partial pressure. The permeability of PFA showed a stronger temperature dependence than that of Kel-F
Keywords :
VLSI; integrated circuit technology; mass spectroscopy; polymers; 25 degC; 75 degC; APIMS; Kel-F; PF; atmospheric pressure ionization mass spectrometer; barrier material; permeant partial pressure; permeation coefficients; polymeric tubing; ultra-high-purity N2 gas flow; Fluid flow; Impurities; Ionization; Mass spectroscopy; Nitrogen; Permeability; Polymers; Temperature dependence; Temperature sensors; Testing;
Journal_Title :
Semiconductor Manufacturing, IEEE Transactions on
