Patent ID: 8747629

Claim:
A method of forming a sensor element in a magnetic device, comprising: (a) sequentially forming a stack of layers comprised of a seed layer, anti-ferromagnetic (AFM) layer, and a SyAP pinned layer having an AP2 layer/coupling layer/AP1 layer configuration on a substrate wherein the AP2 layer contacts said AFM layer; (b) forming a tunnel barrier having a first surface that contacts said AP1 layer and a second surface opposite the first surface; (c) forming a composite free layer having a FL1/FL2/FL3 configuration on the tunnel barrier, said composite free layer is comprised of: (1) a FL1 layer contacting the second surface of the tunnel barrier layer, said FL1 layer comprises Fe (100-X) Co X where x is from 0 to 100 atomic %, or a FeCoM alloy where M is one of Ni, Mn, Tb, W, Hf, Zr, Nb, Si, or B; (2) a FL2 layer formed on the FL1 layer, said FL2 layer comprises (Co 100-V Fe V ) 100-Y B Y where v is 10 to 70 atomic %, and y is from 5 to 40 atomic %, or a CoFeB alloy; and (3) a FL3 layer disposed on the FL2 layer, said FL3 layer is a composite structure represented by (CoB/CoFe) n where n is ≧1 or (CoB/CoFe) m /CoB where m is ≧1.