Patent ID: 8178361

Claim:
A manufacturing method for a magnetic sensor comprising the steps of: forming a planation layer that provides planation by covering a wiring layer of a semiconductor substrate; forming a passivation film on the planation layer; forming a thick film on the passivation film; forming a resist film on the thick film; partially removing the resist film; performing heat treatment on the resist film, thus making terminal surfaces thereof incline; performing etching on the resist film and the thick film at an etching selection ratio of 1:1, thus forming a plurality of channels in the thick film; forming bias magnets forming giant magnetoresistive elements on a planar surface of the thick film as well as slopes, top portions, and bottoms of the channels; forming a giant magnetoresistive element film; positioning the semiconductor substrate, in which the giant magnetoresistive film is formed, close to a magnet array, and subjecting the semiconductor substrate to heat treatment; removing a part of the giant magnetoresistive element film by way of etching, thus forming magneto-sensitive elements forming the giant magnetoresistive elements on the planar surface of the thick film and the slopes of the channels; and forming a protection film.