Method of frame plating and method of forming magnetic pole of thin-film magnetic head

A method of forming a magnetic pole of a thin-film magnetic head provided for forming a layer including a magnetic pole portion, the thin-film magnetic head comprising:

• a medium facing surface that faces toward a recording medium;
• a first magnetic layer and a second magnetic layer magnetically coupled to each other and including magnetic pole portions opposed to each other and placed in regions of the magnetic layers on a side of the medium facing surface, each of the magnetic layers including at least one layer;
• a gap layer provided between the magnetic pole portions of the first and second magnetic layers;
• and a thin-film coil at least a part of which is placed between the first and second magnetic layers, the at least part of the coil being insulated from the first and second magnetic layers;
• the method including the steps of:
• forming a frame using a resist;
• and
• forming the layer including the magnetic pole portion by performing plating through the use of said frame,
• said step of forming the frame including:
• a step of forming a first patterned resist layer by using a first resist containing a material generating an acid;
• and a step of forming a second patterned resist layer by coating said first patterned resist layer with a second resist capable of entering into a crosslinking reaction in the presence of an acid, generating an acid in the first patterned resist layer, forming a crosslinked film in a portion of the second resist near the boundary that touches the first patterned resist layer, and peeling off non-crosslinked portions of the second resist,
• wherein said frame is formed using said first patterned resist layer and said second patterned resist layer;
• and
• said first resist comprises the following compounds (A) to (D):
• (A) an organic solvent;
• (B) a base resin comprising a high molecular compound shown in the following formula (1), the compound having a weight average molecular weight of 10000 to 25000 and a molecular weight distribution of as narrow as 1.05 to 1.25:
• wherein R1 represents a hydrogen atom or a methyl group, R2 represents a group represented by the following formula (2), R3 represents an acid-unstabilizing group different from R2:
• wherein R4 and R5 each independently represent a hydrogen atom or a straight chain or branched alkyl group having 1 to 6 carbon atoms, R6 represents a straight chain, branched or cyclic alkyl group having 1 to 10 carbon atoms, or R4 and R5, R4 and R6 or R5 and R6 may form a ring, wherein, in the case of forming a ring, R4, R5 and R6 each independently represent a straight chain or branched alkylene group having 1 to 6 carbon atoms, x and y respectively denote 0 or a positive number provided that x and y are not 0 at the same time, and z denotes a positive number wherein the following relationships are established between x, y and z:
• 0≦x/(x+y+z)≦0.5, 0≦y/(x+y+z)≦0.5 and 0.4≦z/(x+y+z)≦0.9;
• (C) an acid generating agent;
• and
• (D) an aromatic compound having a group given by the formula ≡C—COOH in its molecule.

A method of forming a magnetic pole of a thin-film magnetic head provided for forming a layer including a magnetic pole portion, the thin-film magnetic head comprising:

• a medium facing surface that faces toward a recording medium;
• a first magnetic layer and a second magnetic layer magnetically coupled to each other and including magnetic pole portions opposed to each other and placed in regions of the magnetic layers on a side of the medium facing surface, each of the magnetic layers including at least one layer;
• a gap layer provided between the magnetic pole portions of the first and second magnetic layers;
• and a thin-film coil at least a part of which is placed between the first and second magnetic layers, the at least part of the coil being insulated from the first and second magnetic layers;
• the method including the steps of:
• forming a layer to be patterned, which will be formed into the layer including the magnetic pole portion;
• forming a mask for etching on said layer to be patterned;
• and
• forming said layer including the magnetic pole portion by patterning said layer to be patterned through dry etching using said mask,
• said step of forming the mask including a step of forming a frame using a resist and a step of performing plating by using said frame to form said mask,
• said step of forming the frame including:
• a step of forming a first patterned resist layer by using a first resist containing a material generating an acid;
• and a step of forming a second patterned resist layer by coating said first patterned resist layer with a second resist capable of entering into a crosslinking reaction in the presence of an acid, generating an acid in the first patterned resist layer, forming a crosslinked film in a portion of the second resist near the boundary that touches the first patterned resist layer, and peeling off non-crosslinked portions of the second resist,
• wherein said frame is formed using said first patterned resist layer and said second patterned resist layer;
• and
• said first resist comprises the following compounds (A) to (D):
• (A) an organic solvent;
• (B) a base resin comprising a high molecular compound shown in the following formula (1), the compound having a weight average molecular weight of 10000 to 25000 and a molecular weight distribution of as narrow as 1.05 to 1.25:
• wherein R1 represents a hydrogen atom or a methyl group, R2 represents a group represented by the following formula (2), R3 represents an acid-unstabilizing group different from R2:
• wherein R4 and R5 each independently represent a hydrogen atom or a straight chain or branched alkyl group having 1 to 6 carbon atoms, R6 represents a straight chain, branched or cyclic alkyl group having 1 to 10 carbon atoms, or R4 and R5, R4 and R6 or R5 and R6 may form a ring, wherein, in the case of forming a ring, R4, R5 and R6 each independently represent a straight chain or branched alkylene group having 1 to 6 carbon atoms, x and y respectively denote 0 or a positive number provided that x and y are not 0 at the same time, and z denotes a positive number wherein the following relationships are established between x, y and z:
• 0≦x/(x+y+z)≦0.5, 0≦y/(x+y+z)≦0.5 and 0.4≦z/(x+y+z)≦0.9;
• (C) an acid generating agent;
• and
• (D) an aromatic compound having a group given by the formula ≡C—COOH in its molecule.