METHOD FOR FORMING WIRING FILM

摘要

Provided is a method for forming a wiring film wherein a taper on a side wall is excellently etched at an angle within a prescribed range, at the time of forming a single layer wiring film composed of pure aluminum or an aluminum alloy. After post-baking, a pure aluminum film or an aluminum alloy film is etched to be in a taper shape having a side wall taper angle of 10-70° by using an etching solution including nitric acid, phosphoric acid, acetic acid and water. The wiring film is formed at a post-baking temperature (x(°C))of 110°C or below, and by having the post-baking temperature and the nitric acid concentration (y(wt%)) in the etching solution satisfy the following inequality (1). 10=[(2/3)x-5y]=70 (1)