Thin-film magnetic head for reducing track width, preventing write fringing and reducing magnetic saturation, and production method thereof

A thin-film magnetic head production method comprising the steps of:

• (a) forming a resist layer on a lower core layer and forming, in said resist layer, a groove having a predetermined width and a predetermined length from the surface opposing a recording medium in a height direction;
• (b) forming, in said groove, a track width regulating section composed of a lower pole layer, a nonmagnetic gap layer, and an upper pole layer stacked in order or composed of a nonmagnetic gap layer and an upper pole layer stacked in order;
• (c) removing said resist layer;
• (d) limiting the width of said track width regulating section to the track width by etching both side faces of said track width regulating section in the track width direction;
• (e) forming an inclined face on the upper surface of said lower core layer extending on both sides of said track width regulating section so as to be inclined away from said track width regulating section to gradually increase the distance from said upper pole layer;
• and
• (f) forming an upper core layer having a width larger than the track width on said track width regulating section.