Process for Making Magnetic Structures
Original Publication Date: 1980-May-01
Included in the Prior Art Database: 2005-Feb-13
The magnetic metallurgy in high density storage devices, like bubble memories and recording heads, usually consists of permalloy. In most cases this metallurgy must be patterned into sub-micrometer circuit elements. Subtractively, the definition of such elements in permalloy is achieved only by ion milling or sputter etching because chemical etching precludes sub-micrometer resolution, and because permalloy is chemically inert to any form of plasma etching. However, due to the nature of physical sputtering, ion milling causes shape defects, like sidewall sloping and troughing, which limit the ultimate pattern resolution and the overall pattern acuity.