Self-aligned contiguous-disk chip using 1µm bubbles and charged-wall functions

Abstract

A fully-operational, contiguous-disk bubble chip is described which employs a self-aligned circuit and simplified fabrication. Only one mask is required to define the propagation structures and all of the current control functions. This not only relaxes the demands on photolithography and reduces the number of process steps, but it also provides for more effective implementation of all device functions. Major-minor loop storage arrays with a 5µm period and 1µm bubbles have been fabricated by conventional photolithographic techniques. Operation at 150 kilohertz has been achieved error-free for 10⁵ read-write operations. © 1979 IEEE