Patent ID: 7813088
Filing Date: 2010-10-12
Classification: B82Y,G01R,G11B,G11C

Abstract:
1. A magnetoresistance effect device comprising: a fixed ferromagnetism layer including an Ru layer positioned on a substrate side and a CoFeB layer formed onto said Ru layer, a free ferromagnetism layer including CoFeB, and a barrier layer including crystal magnesium oxide sandwiched by said fixed ferromagnetism layer and said free ferromagnetism layer, wherein said CoFeB layer in said fixed ferromagnetism layer is positioned on a barrier layer side so as to be in contact with said barrier layer, a layer of said crystal magnesium oxide in the barrier layer is formed so as to have a single structure or high orientation polycrystal structure having no grain boundary in a thickness direction, and said CoFeB in which an amount (b: atomic %) of addition of boron (B) satisfies a condition of 21%≦b≦23% is used for said free ferromagnetism layer.