# US 5,349,745 A · Method of fabricating thin-film magnetic head > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,349,745 A - Document ID: US5349745A - Status: Granted - Kind: A - Application number: 08/069,586 - Filed: 1993-06-01 - Granted: 1994-09-27 - Earliest claimed: 1992-06-09 - Assignees: Hitachi, Ltd. - Inventors: Takashi Kawabe; Eiji Ashida; Moriaki Fuyama; Tadayuki Iwakura; Hiroshi Fukui; Yoshikazu Tsuji; Shunichiro Kuwatsuka; Harunobu Saito; Yoshiki Hagiwara; Issei Takemoto; Masayasu Fujisawa - Web page: https://patentgrep.com/patent/US5349745A ## CPC - G11B 5/3116: {Shaping of layers, poles or gaps for improving the form of the electrical signal transduced, e.g. for shielding, contour effect, equalizing, side flux fringing, cross talk reduction between heads or between heads and information tracks (G11B5/3113, G11B5/245 take precedence)} - G11B 5/3163: {Fabrication methods or processes specially adapted for a particular head structure, e.g. using base layers for electroplating, using functional layers for masking, using energy or particle beams for shaping the structure or modifying the properties of the basic layers} - Y10T 29/49052: by etching - G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R) - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A method of fabricating a thin-film magnetic in which a mask pattern in etching a bottom pole is formed of first and second mask films in this order when viewed from the bottom pole, the first mask film is used for defining, by self-alignment, the length of that portion of the side edge of a top pole which is nearly perpendicular to a magnetic gap, the second mask film makes it possible to etch the bottom pole with high dimensional accuracy, a non-magnetic film is formed on the mask pattern having the bottom pole thereunder and the exposed region of a substrate, and the top pole is formed after the mask pattern has been exposed and removed. ## Claims ### Claim 1 A method of fabricating a thin-film magnetic head, comprising the steps of: forming a first magnetic film on a substrate; forming a first mask film on the first magnetic film; forming a second mask film on the first mask film, a material for the second mask film being different from a material for the first mask film; etching the second mask film, the first mask film and the first magnetic film to a predetermined pattern; forming a non-magnetic film on the second mask film and the exposed region of the substrate; removing a portion of the non-magnetic film to expose the second mask film; removing the second mask film; removing the first mask film; forming a magnetic gap film on at least the first magnetic film; and forming a second magnetic film on the magnetic gap film, the width of the upper edge of the second magnetic film being larger than the width of the lower edge of the second magnetic film, the lower edge of the second magnetic film being contiguous to the magnetic gap film. ### Claim 2 (depends on 1) A method of fabricating a thin-film magnetic head as claimed in claim 1, further comprising a step of forming a tapered portion in the non-magnetic film, simultaneously with the step of removing the second mask film. ### Claim 3 (depends on 1) A method of fabricating a thin-film magnetic head as claimed in claim 1, further comprising a step of forming a tapered portion in the non-magnetic film after the step of removing the second mask film has been completed. ### Claim 4 A method of fabricating a thin-film magnetic head, comprising the steps of: forming a first magnetic film on a substrate; forming a magnetic gap film on the first magnetic film; forming a first mask film on the magnetic gap film; forming a second mask film on the first mask film, a material for the second mask film being different from a material for the first mask film; etching the second mask film, the first mask film, the magnetic gap film and the first magnetic film to a predetermined pattern; forming a non-magnetic film on the second mask film and the exposed region of the substrate; removing a portion of the non-magnetic film to expose the second mask film; removing the second mask film; removing the first mask film; and forming a second magnetic film on the magnetic gap film, the width of the upper edge of the second magnetic film being larger than the width of the lower edge of the second magnetic film, the lower edge of the second magnetic film being contiguous to the magnetic gap film. ### Claim 5 (depends on 4) A method of fabricating a thin-film magnetic head as claimed in claim 4, further comprising a step of forming a tapered portion in the non-magnetic film, simultaneously with the step of removing the second mask film. ### Claim 6 (depends on 4) A method of fabricating a thin-film magnetic head as claimed in claim 4, further comprising a step of forming a tapered portion in the non-magnetic film after the step of removing the second mask film has been completed. ### Claim 7 (depends on 1) A method of fabricating a thin-film magnetic head as claimed in claim 1, wherein at least one of the first magnetic film, the first mask film and the second mask film is formed by selective plating method. ### Claim 8 (depends on 1) A method of fabricating a thin-film magnetic head as claimed in claim 1, wherein flattening processing for the surface of the non-magnetic film is carried out to expose the second mask film. ### Claim 9 A method of fabricating a thin-film magnetic head, comprising the steps of: forming a first magnetic film on a substrate; forming a magnetic gap film on the first magnetic film; forming a first mask film on the magnetic gap film; forming a second mask film on the first mask film, a material for the second mask film being different from a material for the first mask film; etching the second mask film, the first mask film, the magnetic gap film and the first magnetic film to a predetermined pattern; removing the second mask film; forming a non-magnetic film on the first mask film and the exposed region of the substrate; removing a portion of the non-magnetic film to expose the first mask film; removing the first mask film; and forming a second magnetic film on the magnetic gap film, the width of the upper edge of the second magnetic film being larger than the width of the lower edge of the second magnetic film, the lower edge of the second magnetic film being contiguous to the magnetic gap film.