Patent ID: 7810226

Claim:
A manufacturing method of a thin-film magnetic head comprising steps of: forming a main magnetic pole film on a first nonmagnetic layer formed on or above an element formation surface of a substrate; forming a photoresist pattern film used as a mask on said main magnetic pole film; forming a first pattern having a width W TE in a track width direction, obtained by collectively trimming said photoresist pattern film and at least an upper portion of said main magnetic pole film by means of ion beam etching or reactive ion etching; forming a non-magnetic mask film made of a nonmagnetic material having a smaller etching rate than said main magnetic pole film so as to cover said first pattern; forming a second pattern having a width W PA larger than said width W TE of said first pattern, in a track width direction, obtained by collectively trimming said main magnetic pole film and said non-magnetic mask film surrounding said main magnetic pole film by means of ion beam etching or reactive ion etching at least until an upper surface of said first non-magnetic layer is reached; thereafter or at the same time of said forming said second pattern, forming: side surfaces, having a bevel angle, of said main magnetic pole layer; and a lowest surface of the main magnetic pole layer having a width W LE , smaller than said width W TE of said first pattern, in a track width direction, by undercutting said second pattern without changing an upper portion having said width W TE of said first pattern of said main magnetic pole film by means of ion beam etching or reactive ion etching; forming a second non-magnetic film so as to cover said second pattern that has been undercut; and forming a main magnetic pole layer surrounded by said second non-magnetic film by polishing said second non-magnetic film and an upper portion of said main magnetic pole film.