Electron-beam fabrication of high-density amorphous bubble film devices

Abstract

A lowtemperature, all-vacuum process combined with electron-beam lithography suitable for single-level masking devices using 2-μm diameter amorphous bubble films has been developed. A test vehicle which uses 0.75-um wide chevrons and 1-μm wide T.I bars in an 8,000-bit chip configuration, resulting in an areal density of 1x10’ bits/in, was used. Important process features are found to be: (1) laminated NiFe films to obtain low Hc and high magnetoresistive effect when deposited at low substrate temperature, (2) maintenance of low surface temperature during metallization to preserve the integrity of exposed and developed electron-beam resist pattern, and (3) proper resist profile for ease of the lift-off process. Excellent bubble device operating characteristics have been obtained as a result of uniformity in materials and structure resulting from careful control of fabrication parameters. © 1975, IEEE. All rights reserved.