Patent ID: 7126201

Claim:
A magnetic random access memory comprising a plurality of memory cells, each of which comprises: a free layer which has a reversible free spontaneous magnetization; a synthetic ferrimagnetic fixed layer; and a spacer layer formed of non-magnetic material and interposed between said free layer and said synthetic ferrimagnetic fixed layer, wherein said synthetic ferrimagnetic fixed layer comprises: a first pinned layer which has a first fixed spontaneous magnetization fixed in a first direction; and a second pinned layer which has a second fixed spontaneous magnetization fixed in a second direction which is opposite to said first direction, said first pinned layer comprises: a first portion provided to extend said first direction; and a second portion formed on said first portion such that said second portion is aligned in position with said second pinned layer in a direction perpendicular to a surface of a substrate on which said magnetic random access memory is formed, said first pinned layer and said second pinned layer are formed such that said synthetic ferrimagnetic fixed layer does not substantially influence on said free layer due to orange peel effect, when said first fixed spontaneous magnetization is M 1 said second fixed spontaneous magnetization is M 2 and said second pinned layer has a thickness of t 2 , said second portion is formed to have a thickness of (M 2 /M 1 )*t 2 , and said synthetic ferrimagnetic fixed layer is formed such that said synthetic ferrimagnetic fixed layer does not substantially give influence of the magneto-static coupling effect to said free layer.