Effects of spacer layer elastic properties on metallic thin film edge-induced stress gradients in bubble memory devices

Author

Gill, H.S. ; George, P.K. ; Tuxford, A.M.

Author_Institution

Hewlett-Packard´´s Physical Sciences Laboratory, Palo Alto, CA

Volume

18

Issue

5

fYear

1982

fDate

9/1/1982 12:00:00 AM

Firstpage

1004

Lastpage

1007

Abstract

It is well-known that metallization edge-induced stresses can change the uniaxial magnetic anisotropy of a liquid phase epitaxial (LPE) garnet film near the metallization edge. We have investigated this magnetostrictive interaction of patterned metallic films with ion-implanted LPE films by using several different spacer layers such as polyimide, SiO2, Si3N4, and combinations of polyimide and SiO2beneath a Cr-Cu-Cr conductor pattern. It is concluded that the stress eliminating capability of a spacer depends on the hardness parameter $K = frac{E_{s}(1-\\nu\\min{f}\\max {2})}{E_{f}(1-\\nu\\min{s}\\max {2})}$ where $E_{s} , E_{f}$ are Young\´s moduli and $\\nu_{s}, \\nu_{f}$ are Poisson\´s ratios for the spacer and metallic film, respectively. The polyimide spacer with $E_{s} < 10^{11}$ dyn/cm²and with $K \\leq 0.1$ transmits an order of magnitude of smaller stress than a SiO2spacer with $K \\geq 1$ with the stress being more uniformly distributed across the spacer.

Keywords

Magnetic anisotropy; Magnetic bubble memories; Anisotropic conductive films; Garnet films; Magnetic anisotropy; Magnetic films; Magnetic liquids; Metallization; Polyimides; Semiconductor films; Stress; Thin film devices;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/TMAG.1982.1061958

Filename

1061958