Patent ID: 6828639
Filing Date: 2004-12-07
Classification: G11C,H01L

Abstract:
An MRAM cell comprising:a substrate; a first electrode formed adjacent to the substrate; a pinned layer formed on the substrate so as to overlie the first electrode and be electrically coupled therewith; an insulating layer formed on the pinned layer, wherein the insulating layer is formed so as to define a bit recess having a first shape; a sense layer formed by contiguously depositing the sense layer on the insulation layer so as to contour the first shape of the bit recess and then planarizing so as to define the sense layer within the bit recess, wherein the first shape of the bit recess is selected such that when the sense layer is positioned in the bit recess and contour the first shape wherein the resulting regions of the sense layer at the outer perimeter of the bit recess are oriented by the first shape of the bit recess to produce a magnetic field that has a component directed away from the pinned layer; and a second electrode connected to the sense layer, wherein application of voltage differential between the first and the second electrode results in a change in the magnetic state of the sense layer thereby resulting in a detectable change in the resistance of the MRAM cell.