Patent ID: 6654278
Filing Date: 2003-11-25
Classification: G11C

Abstract:
A magnetoresistive tunneling junction memory cell comprising:an electrically insulating material designed to form a magnetoresistive tunneling barrier; a bit magnetic region positioned on one side of the electrically insulating material, the bit magnetic region having a bit magnetic moment that has a polarity in a bit easy axis when there is no applied magnetic field; a reference magnetic region positioned on an opposite side of the electrically insulating material, wherein the electrically insulating material and the bit and reference magnetic regions form a magnetoresistive tunneling junction device (MTJD); and means for inducing an applied magnetic field in the bit and reference magnetic regions; wherein the reference magnetic region has a low aspect ratio and has a reference magnetic moment that is substantially orthogonal to the bit easy axis when the applied magnetic field has a magnitude of zero, at which magnitude the MTJD has a reference magnetoresistance, and wherein the polarity of the bit magnetic moment is reliably indicated by a sign of a change of the magnetoresistance of the MTJD from a rotation of the reference magnetic moment, and the polarity of the bit magnetic moment is not switched, when the applied magnetic field has a sense value that is within a non-switching magnetic field region.