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Proceedings Paper

Development of the water-window imaging x-ray microscope
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Paper Abstract

Silicon nitride (Si3N4) has been demonstrated to be an effective high- temperature anti-oxidant, especially when deposited in its (alpha) -crystalline form. UTRC has developed a pilot scale chemical vapor deposition (CVD) reactor capable of depositing (alpha) -Si3N4 from ammonia (NH3) and silicon tetrafluoride (SiF4) at 1450 C. Coherent anti-Stokes Raman spectroscopy (CARS) has been applied to this reactor which has been fitted with line-of- sight optical access ports. Temperature and concentration measurements have been performed on gas phase species during the deposition of Si3N4. Based on the CARS detection of H2, the importance of high temperature surface (Si3N4) catalyzed decomposition of NH3: 2NH3(Delta )yields3H2 + N2, is established as a competing reaction to: 4NH3 + 3SiF4(Delta) )yieldsSi3N4 + 12HF, in the CVD reactor under deposition conditions. Mass spectroscopic measurements, performed on the reactor exhaust, confirm that the primary gas phase species are N2, H2 and HF. H2 is observed spectroscopically both in the presence and absence of SiF4, and in a variety of precursor composition ratios.

Paper Details

Date Published: 1 July 1991
PDF: 14 pages
Proc. SPIE 1435, Optical Methods for Ultrasensitive Detection and Analysis: Techniques and Applications, (1 July 1991); doi: 10.1117/12.44257
Show Author Affiliations
Richard B. Hoover, NASA/Marshall Space Flight Ctr. (United States)
David L. Shealy, Univ. of Alabama/Birmingham (United States)
Phillip C. Baker, Baker Consulting (United States)
Troy W. Barbee Jr., Lawrence Livermore National Lab. (United States)
Arthur B. C. Walker II, Stanford Univ. (United States)

Published in SPIE Proceedings Vol. 1435:
Optical Methods for Ultrasensitive Detection and Analysis: Techniques and Applications
Bryan L. Fearey, Editor(s)

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