| Autor: |
Ishihara, Yoshio, Umehara, Hitomi, Akira Nishina, Akira Nishina, Tetsuya Kimijima, Tetsuya Kimijima |
| Zdroj: |
Japanese Journal of Applied Physics; November 1997, Vol. 36 Issue: 11 p6999-6999, 1p |
| Abstrakt: |
We developed high pressure ionization mass spectrometry (HPIMS) to monitor trace impurities in nitrogen ( N2) gas in order to establish an ultra-high purity (UHP) N2supplying technology for ULSI fabrication. We also demonstrated that the oxygen ( O2), carbon dioxide ( CO2) and moisture ( H2O) in N2can be measured with a high sensitivity and accuracy using HPIMS. The ion intensities of O2, CO2and H2O in N2with HPIMS was increased about one order of magnitude more than that with atmospheric pressure ionization mass spectrometry (APIMS). The excellent linearity between the ion intensity and O2concentration was obtained with a correlation coefficient over 0.9999 in the range from 5 ppb to 50 ppb. The reproducibility and accuracy of measurement could be improved since the pressure of the ionization chamber was controlled precisely by using HPIMS. |
| Databáze: |
Supplemental Index |
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