Browse Prior Art Database

High Yield Process for Single Level Mask Bubble Devices

IP.com Disclosure Number: IPCOM000085376D
Original Publication Date: 1976-Mar-01
Included in the Prior Art Database: 2005-Mar-02
Document File: 2 page(s) / 27K

Publishing Venue

IBM

Related People

Ahn, KY: AUTHOR [+2]

Abstract

A method has been devised for making magnetic bubble devices and their sensors, so that the final devices are more tolerant to errors made in fabricating them.

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High Yield Process for Single Level Mask Bubble Devices

A method has been devised for making magnetic bubble devices and their sensors, so that the final devices are more tolerant to errors made in fabricating them.

In the making of a magnetic bubble device having the conventional "I" and "T" bar configurations for propagation and transferring of bubbles in a bubble film, as well as conventional bubble sensors, it is necessary to employ a NiFe film over the bubble film, the latter being made of garnet or other bubble-supporting material.

A gold film, serving as an electrical conductor, is applied to the NiFe film. However, if the NiFe film is in direct contact with the Au film, electrical shorting between the two metals will destroy the sensing operation of the bubble device. In fabricating such devices by ion milling, a process-tolerant layer is desirable. Therefore a thin layer of SiO(2) is deposited between the NiFe and Au.

The figure illustrates how this SiO protective film is used to assist in more reliably carrying out subsequent processes needed to complete a bubble device. A bubble-supporting film 2 has a NiFe film 4, about 500 - 3000 Angstroms thick, deposited thereon. A 500 Angstrom thick film 6 of SiO(2) separates a 3000 Angstrom thick film 8 of Au from the NiFe film 4. By well-known lithography techniques, a T bar 10, and I bar 12 and a bubble sensing layer 14, all made of permalloy, are covered with a layer of photoresist 16.

When the bubble device i...