A method of coating contact holes in MEMS and micro-machining applications comprises: providing an insulating layer above an integrated circuit; providing a resist layer above the insulating layer; patterning and developing the resist layer in order to form at least one contact aperture in the resist layer; isotropically etching the insulating layer using the resist layer as a mask, so that a contact hole is formed in the insulating layer; and coating the walls of said contact hole with a layer of metal.