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Fabrication of Dielectric Spacer for Garnet Bubble Devices

IP.com Disclosure Number: IPCOM000077917D
Original Publication Date: 1972-Oct-01
Included in the Prior Art Database: 2005-Feb-25
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Sadagopan, V: AUTHOR [+2]

Abstract

Fabrication of circuits that manipulate cylindrical magnetic domains or bubbles in epitaxial garnet films has been achieved. See V. Sadagopan et al, "High Density Bubble Domain Shift Register," 17th Annual Magnetism Conference paper, Chicago, Nov. 16-19, 1971. Such circuits utilize a T-bar configuration of permalloy thin film, placed over an insulator (dielectric spacer) that is in contact with the epitaxial garnet film. Since the dielectric spacer is sandwiched between the garnet and permalloy films, its physical properties have to be compatible with both the garnet and the permalloy. For example, a good thermal expansion match between the dielectric spacer and the garnet is essential, so that the interfacial stress is of the right sign which is critical with respect to optimum device operation.

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Fabrication of Dielectric Spacer for Garnet Bubble Devices

Fabrication of circuits that manipulate cylindrical magnetic domains or bubbles in epitaxial garnet films has been achieved. See V. Sadagopan et al, "High Density Bubble Domain Shift Register," 17th Annual Magnetism Conference paper, Chicago, Nov. 16-19, 1971. Such circuits utilize a T-bar configuration of permalloy thin film, placed over an insulator (dielectric spacer) that is in contact with the epitaxial garnet film. Since the dielectric spacer is sandwiched between the garnet and permalloy films, its physical properties have to be compatible with both the garnet and the permalloy. For example, a good thermal expansion match between the dielectric spacer and the garnet is essential, so that the interfacial stress is of the right sign which is critical with respect to optimum device operation. The selection of a nonmagnetic, insulating garnet of composition similar to the epitaxial magnetic garnet film is suggested by use of a chemical vapor deposition (CVD).

More specifically, magnetic garnet film, such as (Gd, Y)(3) (Fe, Ga)(5)O(12) is grown on gadolinium gallium garnet (GGG) substrates, as described by R. C. Taylor et al, Appl. Physics Letters 19, 361 (1971). After the ferromagnetic material is grown, HCl flow over the iron source is terminated and the HCl flow over the gallium source is increased. This results in the growth of an insulating film of (Gd, Y)(3) Ga(5)O(12) on the magnetic film. It is...