Patent ID: 7369376
Filing Date: 2008-05-06
Classification: G11C

Abstract:
1. A magnetic tunnel junction device, comprising: a lower conductive electrode; a seed layer on said lower conductive electrode; an antiferromagnetic layer on said seed layer; an AP2 layer on said antiferromagnetic layer; an antiferromagnetic coupling layer on said AP2 layer; an AP1 layer on said antiferromagnetic coupling layer; a tunneling layer of aluminum oxide on said AP1 layer; on said tunneling layer, a free layer comprising first and second free sub-layers; said first free sub-layer further comprising a layer of CoFeB containing at least 10 atomic percent boron, having an amorphous structure, a thickness of at least 15 Angstroms, and a magnetostriction constant whose absolute value is no greater than about 1.5×10 said second free sub-layer further comprising a layer of material selected from the group consisting of CoB, CoNb, and CoNbHf, having an amorphous structure, a thickness of at least 15 Angstroms, and a magnetostriction constant whose absolute value and sign are negative such that it effectively cancels out magnetostriction due to said first free sub-layer, whereby said magnetic tunnel junction device has a magnetostriction constant whose absolute value is greater than 0.5×10 a capping layer on said free layer; and an upper conductive electrode on said capping layer.