Cathode Sputtering - A Commercial Application

A L T H O U G H the process of electrostatic deposition of metals by high voltages in a partial vacuum, commonly known as cathode sputtering, has been known for more than a half century, it has heretofore found but little commercial application. Rather extensive use of it has, however, been made in physics research laboratories for such purposes as the production of highly reflecting surfaces on mirrors and prisms, for spectrometers, interferometers, etc., and the making of extremely thin metal films for fundamental studies in atomic structure and electron theory. Sputtering has also been used in the manufacture of very fine conducting quartz fibres for suspensions in sensitive instruments such as quadrant and string electrometers, galvanometers, and electrocardiographs, and, to some extent, for etching certain metals. In the following paragraphs it is intended to give a brief explanation of the process and a description of a commercial application in the production of diaphragms for certain microphones. THEORY