Coating of Si3N4 fine particles with AlN by fluidized bed-CVD

Abstract

Agglomerates of 100-250 μm consisting of Si3N4 primary particles of 0.76 μm were made with a rotary vibrating sieve. Si3N4 fine particles were coated with A1N by gas phase reaction with AlCl3 and NH3 in some fluidized beds of the agglomerates. The cross sectional distribution of A1N in the agglomerate was measured by EPMA analysis. As a result, uniform deposition of A1N was obtained at a relatively low reaction temperature and low gas velocity.