Fabrication and testing of trilayers with a high deposition rate plasma-polymerized spacer

Abstract

A great deal of effort has recently been directed toward the development of digital optical storage systems using Ga-Al-As lasers for both reading and writing. The relatively low output power of these devices necessitates sensitive optical storage media if reasonable data rates are to be achieved. At the same time, it is desirable that the material exhibit archival properties. One method of reducing the writing energy for a wide variety of materials is to incorporate them within an optical structure that improves the optical efficiency. In particular, trilayer structures consisting of an aluminum layer 30 nm thick, a spacer layer about 100 nm thick and a thin storage layer offer the potential of improved sensitivity for a wide range of active materials, but their use requires the fabrication of a low thermal conductivity optically clear spacer layer approximately one-quarter wave thick. Because of manufacturing considerations, it is desirable that this layer be deposited at relatively high rates in an inexpensive process. Here we describe the investigation of the plasma polymerization of various monomers for this purpose. It has been found that stable films of perfluoro-2-butene can be deposited at rates greater than 1 nm s-1. Trilayer structures using this material as the spacer layer are compared with more conventional materials. © 1983.