Patent ID: 7045368
Filing Date: 2006-05-16
Classification: G11C,H01L

Abstract:
1. A method of fabricating an MRAM cell structure having a plurality of MTJ elements each with an uppermost cap layer that has a certain thickness whereby the certain thickness is controlled within a range of about +/−5 Angstroms, comprising: (a) providing a plurality of MTJ elements on a substrate and depositing an insulation layer on the substrate to a level that covers the MTJ elements including a top surface of said cap layer; (b) performing a CMP step to planarize said insulation layer wherein the planarized insulation layer has a first thickness above the top surface of said cap layer; and (c) performing an etch back step to reduce the thickness of said insulation layer wherein the insulation layer is planarized at a second thickness below the top surface of said cap layer.