Patent ID: 6757962
Filing Date: 2004-07-06
Classification: B82Y,G01R,G11B,H01F,Y10T

Abstract:
A method for manufacturing a magnetic field sensing element comprising the steps of:(a) forming a laminate by sequentially laminating a first antiferromagnetic layer, a pinned magnetic layer, a non-magnetic layer, a free magnetic layer comprising a first free magnetic layer, a non-magnetic intermediate layer and a second free-magnetic layer, and a second antiferromagnetic layer; (b) generating an exchange coupling magnetic field in the first and second antiferromagnetic layers by applying a heat treatment at a first heat treatment temperature, while applying a first magnetic field to the laminate in a perpendicular direction with respect to a track width direction, thereby fixing a direction of magnetization of the pinned magnetic layer and a direction of magnetization of the free magnetic layer in said perpendicular direction, wherein the exchange coupling magnetic field of the first antiferromagnetic layer is larger than the exchange coupling magnetic field in the second antiferromagnetic layer; (c) heat treating at a second heat treatment temperature that is higher than the first heat treatment temperature while applying a second magnetic field that is larger than the exchange coupling magnetic field of the second antiferromagnetic layer and smaller than the exchange coupling magnetic field of the first antiferromagnetic layer in the track width direction, thereby endowing the free magnetic layer with a longitudinal bias magnetic field in a direction that intersects the direction of magnetization of the pinned magnetic layer; (d) forming a pair of electrode layers on the laminate separated by a predetermined distance; and (e) removing a portion of the laminate exposed between the pair of the electrodes to a depth about midway into the second free magnetic layer.