Ion Plating of Copper Film on Ultrasmooth Nonconducting Substrates

A method of obtaining copper films on ultrasmooth insulators like polished ferrites and ceramics using ion plating is reported. The films exhibit excellent bond strength and have high etching resolution and uniformity. The procedure adopted, besides eliminating one of the intermediate steps of precoating the insulator with certain metals/alloys prior to coating with copper, also reduces microwave losses. The copper coatings thus obtained satisfy all the requirements for their use in microwave integrated circuit technology.