Patent ID: 7603764

Claim:
A method of manufacturing a thin film magnetic head including: a first magnetic layer and a second magnetic layer which are magnetically coupled to each other and have two magnetic poles facing each other with a gap layer in between near and in a recording-medium-facing surface to be faced with a recording medium; and a thin film coil provided between the first and second magnetic layers with an insulating layer in between, the first magnetic layer having a predetermined magnetic layer portion including a uniform width portion which extends away from the recording-medium-facing surface and determines a write track width on the recording medium, wherein forming the predetermined magnetic layer portion includes the steps of: forming a magnetic material layer; selectively forming a first magnetic film for constituting one part of the predetermined magnetic layer portion, on the magnetic material layer; and selectively etching the magnetic material layer by using the first magnetic film as a mask, thereby selectively forming a second magnetic film for constituting the other part of the predetermined magnetic layer portion, wherein the first magnetic film is in contact with the magnetic material layer, the step of selectively etching the magnetic material layer involves reactive ion etching in a gaseous atmosphere containing at least one of chlorine and boron trichioride, the step of selectively etching takes place at a temperature between 50 and 300° C. inclusive.