Patent ID: 7476919

Claim:
A magnetic random access memory (MRAM) cell structure formed on a substrate, comprising: (a) a first conductive layer formed within a first insulation layer on said substrate, said first conductive layer is comprised of an array of parallel first lines having a first width that are coplanar with said first insulation layer; (b) an array of magnetic tunnel junctions (MTJs) formed on said parallel first lines, said MTJs have a length and width and are comprised of a bottom layer, a free layer on the bottom layer, and a cap layer on the free layer wherein the cap layer has a top surface and a bottom surface and the thickness “y” between the top surface and bottom surface is controlled within a range of about “y”+/−5 Angstroms for all of said MTJs in said MRAM structure; (c) a second insulation layer formed on said first insulation layer and on said first conductive layer, said second insulation layer contacts said cap layer and has an entire planar top surface which is below the top surface of said cap layer; and (d) a second conductive layer comprised of an array of parallel second lines having a second width and aligned in a direction perpendicular to said first lines and wherein the array of second lines is formed over the MTJs so that an MTJ is located at each location where a second line crosses over a first line.