Mated film memory: implementation of a new design and production concept

Abstract

A high performance computer memory must operate at high speed, require a minimum amount of power, and be capable of operating under extreme environmental conditions. Thin film memories meet these requirements, however, anyone who expected them to become the primary memory technology was certainly premature. Despite its superior performance features, the thin film memory has encountered producibility problems which have prevented it from becoming cost competitive. Univac has developed the MATED FILM memory concept and a continuous vacuum deposition system which together have overcome previous producibility obstacles and now make the evaporated film memory a serious contender for main store applications. The features which are new and unique to this approach are: 1. Economical continuous deposition for 16-hour periods with all deposition parameters maintained in equilibrium. 2. The closed-flux path design has wide operating margins and provides an exceptionally low susceptibility to process variations. 3. Changing the film array organization from a word-bit matrix to a bit-slice array has greatly reduced the number of connections and process steps required to fabricate the memory stack.