METHOD FOR PREPARING ALUMNA COATING FILM HAVING alpha-TYPE CRYSTAL STRUCTURE AS PRIMARY STRUCTURE

摘要

A method for preparing an alumina coating film having an alpha-type crystal structure as a primary structure wherein the alumina coating film is formed on a substrate through the sputtering of an aluminum metal in an atmosphere containing an oxidizing gas, characterized in that it comprises a step of forming a film under conditions suitable for the formation of an alumina having alpha-type crystal structure as an initial step of the film formation, for example, an alumina having alpha-type crystal structure is formed under an electric discharge in a poisoning mode only in the initial step of the film formation. The method allows the film formation with good efficiency of an alumina coating film having an alpha-type crystal structure as a primary structure.