Magnetostatically coupled thin-film magnetic memory devices

Abstract

Abstract A multilayer magnetostatically coupled thin-film magnetic memory device comprising, in succession, a first magnetic film, a chromium-copper alloy conducting layer having a reasonably low resistivity, a smoothing layer, and a second magnetic film. Due to the presence of chromium in the chromium-copper alloy forming the conducting layer, when the second magnetic film is subsequently formed on the smoothing layer at an elevated temperature, the resulting grain growth and surface roughness of the chromium-copper alloy conducting layer are less severe than with other known metals having reasonably low resistivity values (e.g., copper, silver, gold, and aluminum) previously suggested for use as conducting layers in magnetostatically coupled thinfilm magnetic memory devices. Consequently, the effects of grain growth and surface roughness of the chromium-copper alloy conducting layer on the static magnetic properties of the second magnetic film are less severe than heretofore, and a smaller combined thickness of the conducting layer and smoothing layer is required to make the values of the static magnetic properties of the first and second magnetic films nearly equal. As a further result of the smaller combined thickness of the conducting and smoothing layers made possible by the use of chromium in the chromium-copper alloy, an improved magnetostatic coupling between the two magnetic films is obtained. An alternative multiplayer magnetostatically coupled thin-film magnetic memory device having no smoothing layer is also disclosed for use in less stringent applications where very close matching of the values of the static magnetic properties of the two magnetic films is not required.

Inventors

• 👤 Dennis M Franklin
• 👤 Richard M Hornreich
• 👤 Harvey Rubinstein

Bibliographic Details