Patent ID: 9082872
Filing Date: 2015-07-14
Classification: G01R,H01F,H01L

Abstract:
1. A magnetic tunneling junction (TMR) stack comprising: a seed layer; a pinning layer formed on said seed layer; a synthetic antiparallel (SyAP) layer formed on said pinning layer and magnetically coupled thereto, wherein said SyAP layer is formed as an antiferromagnetically coupled pair of ferromagnetic layers denoted by AP1 and AP2, said ferromagnetic layers being separated by a non-magnetic coupling layer, and wherein said AP2 layer is formed on said pinning layer; and wherein said AP1 layer incorporates multiple layers of CoFe and CoFeB interspersed with a first plurality of insertion layers of Fe or FeX or multiple laminations of Fe or FeX wherein X is one or more of metallic, non-magnetic elements selected from Ta, Hf, V, Co, Mo, Zr, Nb or Ti and wherein a total atom percent of X is less than 50%; a tunneling barrier layer formed on said AP1 layer; a ferromagnetic free layer formed on said tunneling barrier layer, said ferromagnetic free layer comprising multiple layers of CoFeB, CoFe and NiFe, interspersed with a second plurality of insertion layers of Fe or FeX or multiple laminations of Fe or FeX wherein X is one or more of metallic, non-magnetic elements selected from Ta, Hf, V, Co, Mo, Zr, Nb or Ti and wherein a total atom percent of X is less than 50% and wherein said second plurality of insertion layers have a body centered cubic (BCC) crystalline structure and are positioned so as to control interdiffusion of B and Ni, and maintain crystallinity and wettability of said tunneling barrier layer; and a capping layer formed on said ferromagnetic free layer.