Patent ID: 6844998

Claim:
A magnetoresistive sensor including, on a substrate, a lower shield layer made of a magnetic material; a lower gap layer made of an insulating material and formed on said lower shield layer; a multilayered film comprising an antiferromagnetic layer, a pinned magnetic layer having a magnetized direction pinned by an exchange coupling magnetic field produced upon interaction with said antiferromagnetic layer, a nonmagnetic material layer, and a free magnetic layer of which magnetization is varied depending on an external magnetic field, said multilayered film being formed on said lower gap layer; an electrode portion for supplying an electric current to said multilayered film; an upper gap layer made of an insulating material and formed on said multilayered film and said electrode portion; and an upper shield layer made of a magnetic material and formed on said upper gap layer, said electrode portion comprising a plurality of electrode layers successively formed as plural pairs of electrodes in an area overlapping said multilayered film in a track width direction or areas on both sides of said multilayered film such that each pair of electrodes are spaced apart from each other by a predetermined spacing in the track-width direction and the spacing between each pair of electrodes in the track-width direction, is larger in the electrode layer located at a higher level, wherein a distance between said upper shield layer and said lower shield layer in an area, which overlaps only a lowermost one of said plurality of electrode layers, is G 1 s , and a distance between said upper shield layer and said lower shield layer at a position in alignment with a center of said multilayered film is G 1 c , a difference in value between G 1 s and G 1 c is set to be not larger than a predetermined value such that an effective track width of the magnetoresistive sensor has a value equal to 0.17 μm or below.