Thin-film magnetic head for track width not more than 1 μm on recording medium and method for making the same

A thin-film magnetic head comprising:

• an upper core layer and a lower core layer extending from a back region to a magnetic pole end region, the upper core layer and the lower core layer being exposed at an opposing face opposing a medium and being connected to each other in the back region;
• a coil provided on the periphery of the connection of the upper core layer and the lower core layer;
• a gap layer provided between the upper core layer and the lower core layer in the magnetic pole end region;
• an insulating layer formed on the lower core layer;
• and
• a groove formed in the magnetic pole end region of the insulating layer and extending from the opposing face to the back region;
• wherein the groove forms an opening in the lower core layer, the upper core layer, and the opposing face, and has a main portion having a cross-sectional size which is substantially the same as the size of the opening at the opposing face;
• a lower magnetic layer, the gap layer, and a upper magnetic layer are deposited in the groove;
• the lower magnetic pole layer is in contact with the lower core layer and the upper magnetic pole layer is in contact with the upper core layer such that the upper magnetic pole layer constitutes an upper magnetic pole end and the lower magnetic pole layer constitutes a lower magnetic pole end;
• in the exposed section at the opposing face, a length of the lower magnetic pole layer in a track width direction is larger than a length of the upper magnetic pole layer in the track width direction, and
• wherein, at the opposing face, the difference between the length of the lower magnetic pole layer in the track width direction and the length in the track width direction of the upper magnetic pole layer in. contact with the gap layer is not greater than a thickness of the gap layer.