Patent ID: 6503373
Filing Date: 2003-01-07
Classification: C23C,Y10T

Abstract:
A method of applying a coating by physical vapour deposition onto an article of organic material, or onto an article of another composition coated with such organic material,characterised in thata Cr layer is deposited on the article prior to deposition of said coating to form a diffusion barrier for water coming from said article, said Cr layer itself being deposited by a physical vapour deposition process comprising at least the following steps: a) depositing a first layer of Cr on said article in a physical vapour deposition apparatus using an arc evaporator or cathode sputtering source, or a combined arc evaporator and cathode sputtering source, using zero bias, and b) subsequently applying a negative bias voltage to said article having said first layer of Cr and depositing a further layer of Cr on said first layer using Cr ions in the same physical vapour deposition apparatus, wherein the step a) is followed by a treatment step in the same apparatus in which a negative bias higher than that of step b) is applied to said first Cr layer and said first Cr layer is bombarded with Cr ions to produce at least one of the following effects: plasma activation of the free surface of the first Cr layer etching of the free surface of the first Cr layer, implantation of Cr ions into the first Cr layer implantation of Cr ions into a surface layer of the article beneath said firs Cr layer densification of said first Cr layer.