Mask schemes for patterning magnetic tunnel junctions

Abstract

Methods of patterning magnetic tunnel junctions (MTJ's) of magnetic memory devices that avoid shorting magnetic memory cells to upper levels of conductive lines during etching processes. One method involves using a hard mask having two material layers to pattern the lower magnetic material layers of an MTJ. The first material of the hard mask is thin and comprises an etch-resistant material. The second material of the hard mask deposited over the first material is thicker and is less etch-resistant than the first material. At least a portion of the second material is sacrificially removed during the etch process of the lower magnetic material layers. A conformal or non-conformal material may be used as the second material of the hard mask. The hard mask used to pattern lower magnetic materials of an MTJ may comprise a single layer of non-conformal material.