Patent ID: 8264800
Filing Date: 2012-09-11
Classification: B82Y,G01R,G11B,H01F,H01L

Abstract:
1. A magnetic field detecting element comprising a substrate, a first lower layer, a second lower layer, a tunnel barrier layer, and an upper layer, wherein said first lower layer, said second lower layer, said tunnel barrier layer, and said upper layer are stacked adjacent to each other in this order such that said first lower layer is located nearer from said substrate than said upper layer, wherein a magnetization direction of said first and second lower layers is fixed relative to an external magnetic field, and a magnetization direction of the upper layer can be changed in accordance with said external magnetic field such that a magnitude of said external magnetic field is detected based on a change in resistance relative to a sense current, said change in resistance depending on said external magnetic field, wherein said first lower layer is made of CoFeB; said second lower layer is made of ferrocobalt and has a film thickness that ranges approximately between 0.2 and 1.5 nm, said second lower layer being formed in a substantially amorphous state and being in touch with said first lower layer and said tunnel barrier layer on both sides; and an atomic percent of cobalt in said second layer is approximately between 80% and 90%.