Patent ID: 7582942
Filing Date: 2009-09-01
Classification: G11C,H01L

Abstract:
1. A low cost flux concentrator, comprising: an MTJ stack, including a capping layer having a top surface, a bottom electrode, and a dielectric layer, having a top surface, that encapsulates said MTJ stack and extends above said capping layer; in said dielectric layer, a trench, having vertical sidewalls, that is longer and wider than said capping layer and that extends downwards as far as said capping layer top surface; said trench being filled with a conductive material that serves as a bit line that passes over said MTJ stack and that has a top surface coplanar with said dielectric top surface; an insulating layer on said coplanar surfaces; a ferromagnetic layer on said insulating layer; and on said ferromagnetic layer, an antiferromagnetic layer that serves to keep said ferromagnetic layer magnetized in a direction parallel to said bit line, thereby providing a domain stabilizing field.