Chapter 47. Laser Vapor Phase Synthesis of Submicron Silicon and Silicon Nitride Powders from Halogenated Silanes
- John B. Wachtman Jr.
Published Online: 28 MAR 2008
Copyright © 1988 The American Ceramic Society, Inc.
Proceedings of the 12th Annual Conference on Composites and Advanced Ceramic Materials, Part 1 of 2: Ceramic Engineering and Science Proceedings, Volume 9, Issue 7/8
How to Cite
Bauer, R. A., Smulders, R., Geus, E. R., Van Der Put, P. J., Becht, J. G. M. and Schoonman, J. (1988) Laser Vapor Phase Synthesis of Submicron Silicon and Silicon Nitride Powders from Halogenated Silanes, in Proceedings of the 12th Annual Conference on Composites and Advanced Ceramic Materials, Part 1 of 2: Ceramic Engineering and Science Proceedings, Volume 9, Issue 7/8 (ed J. B. Wachtman), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470310496.ch47
- Published Online: 28 MAR 2008
- Published Print: 1 JAN 1988
Print ISBN: 9780470374801
Online ISBN: 9780470310496
- tensile stress;
- nucleation angles;
- residual compression
In the state of the art laser synthesis process for silicon, silicon nitride, and silicon carbide, silane is used as a gaseous reactant. Zn order to replace SiH4by chlorinated silanes we have studied the lasersynthesis of Si3N4 from mixtures of SiH2Cl2and NH3, and SiCl4and NH3using a 150 W cw CO2-laser. At room temperature chlorinated silanes readily react with NH, to form Si(NH)2. A laser reactor was developed in which the reactant gases were mixed in the laser beam, thus preventing the formation of Si(NH)2. A concentric N2gas stream was utilized to guide the ceramic powders into a high-temperature electrostatic precipitator in which Si3N4was separated from the waste product NH4Cl. A major problem in utilizing chlorinated silanes is their poor absorption of the CO2-laser radiation (10.6 μm). SF6 has been explored for use as an inert sensitizer.
Particle sizes of the amorphous powders were of submicron dimensions, spherical and nearly monodisperse. The sizes of the particles were studied by TEM and BET analysis. The powders were analyzed by ZR-spectroscopy, X-ray fluorescence, XRD, and EDX.