Patent ID: 7005691

Claim:
A magnetoresistance element, comprising: a non-magnetic layer made of a non-magnetic insulating film; a first ferromagnetic layer and a second ferromagnetic layer formed so as to sandwich the non-magnetic layer; a first electric conductor formed so as to be brought into contact with substantially the center of the surface opposite to the non-magnetic layer of the first ferromagnetic layer; a second electric conductor formed so as to be brought into contact with the surface opposite to the non-magnetic layer of the second ferromagnetic layer; and an insulator formed so as to cover at least the side surfaces of the first ferromagnetic layer and the non-magnetic layer; wherein at least one of the first ferromagnetic layer and the second ferromagnetic layer is magnetized along the direction parallel to the first ferromagnetic layer and the second ferromagnetic layer, the magnetization of one of the first ferromagnetic layer and the second ferromagnetic layer is easily inverted by a magnetic field applied from the outside and another is not easily inverted by a magnetic field applied from the outside, the magnetoresistance element is operated by a current flowing from the first electric conductor to the second electric conductor through the first ferromagnetic layer, the non-magnetic layer and the second ferromagnetic layer, the first electric conductor and the second electric conductor are electrically insulated from each other by the insulator except that the first electric conductor is kept in electric contact with the second electric conductor by a current flowing through the first ferromagnetic layer, the non-magnetic layer and the second ferromagnetic layer, the insulator is formed so as to cover the peripheral edge of the surface of the first ferromagnetic layer, the ratio of the area of the surface covered with the insulator of the first ferromagnetic layer is 5% or more and 60% or less relative to the area of the entire surface of the first ferromagnetic layer, a current of at least 1×10 5 amperes/cm 2 flows from the first electric conductor to the second electric conductor through the first ferromagnetic layer, the non-magnetic layer and the second ferromagnetic layer, at the end of the insulator formed so as to cover the peripheral edge of the surface of the first ferromagnetic layer, a curve having a radius of curvature of 5 nm or more is formed, and the first electric conductor is curved along the curve and smoothly comes into contact with the first ferromagnetic layer.