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Coupled NDRO Magnetic Film Memory

IP.com Disclosure Number: IPCOM000073529D
Original Publication Date: 1970-Dec-01
Included in the Prior Art Database: 2005-Feb-22
Document File: 2 page(s) / 45K

Publishing Venue

IBM

Related People

Kump, HJ: AUTHOR [+2]

Abstract

The memory is formed by the intersection of a word line and a bit-sense line and two magnetic film pairs, one pair being below and the other above the bit-sense line. The films exhibit uniaxial anisotropy or an easy axis in a direction perpendicular to and a hard axis parallel to the length of the bit-sense line. Each pair includes a hard film, which may be made of NiFeCo, with a high anisotropy field H(k) and a soft film, which may be a NiFe film, with a low H(k). The an isotropy fields are in a ratio of about 3:1. Hard and soft films of each pair are separated by a nonmagnetic layer having a thickness from about 0 to 500 angstroms but preferably between 200 and 300 angstroms. The nonmagnetic layer may be made of a conductive material, such as copper, or of an insulating material, such as SiO.

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Coupled NDRO Magnetic Film Memory

The memory is formed by the intersection of a word line and a bit-sense line and two magnetic film pairs, one pair being below and the other above the bit- sense line. The films exhibit uniaxial anisotropy or an easy axis in a direction perpendicular to and a hard axis parallel to the length of the bit-sense line. Each pair includes a hard film, which may be made of NiFeCo, with a high anisotropy field H(k) and a soft film, which may be a NiFe film, with a low H(k). The an isotropy fields are in a ratio of about 3:1. Hard and soft films of each pair are separated by a nonmagnetic layer having a thickness from about 0 to 500 angstroms but preferably between 200 and 300 angstroms. The nonmagnetic layer may be made of a conductive material, such as copper, or of an insulating material, such as SiO. The four magnetic films may be of substantially equal thickness, e.g., each of 600 angstroms, but it may be desirable to have the soft film of greater thickness. Insulation layers are provided between the lower NiFeCo film and a conductive ground plane, between the lower NiFe film and the bit-sense line and between the upper NiFe film and the word line. The two film pairs are separated by approximately three microns and, if desired, a ferrite keeper may be disposed above the word line. Well known plating or evaporation processes, or combinations thereof, may be used to fabricate the memory.

In operation, information is written into the me...