Patent ID: 6896974

Claim:
A magnetic field sensor comprising: a pair of magnetic shields arranged apart from each other with a gap and serving as a negative electrode and a positive electrode, respectively; a magnetoresistive element arranged between the pair of magnetic shields and including a magnetization free layer, a nonmagnetic intermediate layer, a magnetization pinned layer, and an antiferromagnetic layer; a nonmagnetic conductive layer for the negative electrode arranged between the magnetic shield for the negative electrode and the magnetoresistive element and including a first metal layer formed in contact with the magnetoresistive element and a second metal layer formed in contact with the first metal layer, the first metal layer containing at least one metal selected from the group consisting of Ta, Ti, Cr, V, Mo and W, and the second metal layer containing at least one metal selected from the group consisting of Au, Ag and Cu; and a nonmagnetic conductive layer for the positive electrode arranged between the magnetic shield for the positive electrode and the magnetoresistive element and including a first metal layer formed in contact with the magnetoresistive element and a second metal layer formed in contact with the first metal layer, the first metal layer containing at least one metal selected from the group consisting of Ta, Ti, Cr, V, Mo and W, the second metal layer containing at least one metal selected from the group consisting of Au, Ag and Cu, and the thickness of the first metal layer being 1 nm or less and the thickness of the second metal layer being not greater than that of the first metal layer.