Patent ID: 6120843
Filing Date: 2000-09-19
Classification: C23C,Y02T

Abstract:
A method of forming a coating on a workpiece by gas phase diffusion, comprising the following steps:a) arranging both a workpiece and a first metal halide compound source within the same reaction chamber in a reaction vessel;b) establishing a temperature gradient between said workpiece and said source such that said workpiece is at a higher temperature than said source;c) establishing in said reaction chamber a closed loop circulation flow of a gas containing a metal halide compound in a circulation loop between said source and said workpiece and back to said source by means of thermal convection of said gas driven by said temperature gradient, so as to convey said metal halide compound in said gas from said source to said workpiece; andd) reacting said metal halide compound at said workpiece to form said coating on said workpiece.