US Patent 7459095 Opaque chrome coating suitable for etching

A substrate includes an opaque chrome coating on a surface of the substrate dry-etched to form an aperture, wherein chrome in the aperture is below detectable limit. A method of forming an opaque chrome coating having at least two layers on a substrate includes depositing an initial chrome layer having a thickness of less than 10 nm on the substrate without ion-assist or with undetectable ion-assist, and then depositing the remainder of the at least two layers, with or without ion-assist, to form an opaque chrome coating.