Patent ID: 6040012
Filing Date: 2000-03-21
Classification: C23C

Abstract:
A process for preparing a multilayer coating on a substrate comprising a stack of at least two different layers, each layer selected from the group consisting of titanium nitride and aluminum titanium nitride, said process comprising continuously and in a single operation applying said multilayer coating on said substrate in an enclosure, wherein each layer of said multilayer coating is formed by chemical vapor deposition from a gaseous mixture comprising hydrogen, titanium chlorides, aluminum chlorides, and a reducing gas selected from the group consisting of nitrogen and ammonia, wherein said titanium chlorides and aluminum chlorides are obtained by chlorination of a single charge of titanium and aluminum alloy, and wherein the reducing gas to hydrogen molar ratio in the gaseous mixture is modified for each layer so that the amount of aluminum in each said layer of said multilayer coating is varied, thereby producing either said titanium nitride when no aluminum is provided in the layer by said modification of said reducing gas to hydrogen molar ratio or said aluminum titanium nitride when aluminum is provided in the layer by said modification of said reducing gas to hydrogen molar ratio.