Abstract: A top pole layer in a write head includes, in a pole portion, a first layer having surfaces one of which is adjacent to a write gap layer, a second layer having surfaces one of which is adjacent to the other surface of the first layer, and a third layer having surfaces one of which is adjacent to the other surface of the second layer. The first to third layers have different saturation flux densities such that the closer the layer to the write gap layer, the higher saturation flux density.

Abstract: A track width defining layer for defining a write track width of a thin-film magnetic head is made of a CoNiFe film formed through electroplating. The CoNiFe film contains 60 to 75 weight % cobalt, 10 to 20 weight % nickel, and 10 to 20 weight % iron, and has a crystal structure that is a mixture of a body-centered cubic structure phase and a face-centered cubic structure phase, in which Ib/If falls within the range of 0.3 to 0.7 inclusive where Ib represents the intensity of an X-ray diffracted from a (110)-plane of the body-centered cubic structure and If represents the intensity of an X-ray diffracted from a (111)-plane of the face-centered cubic structure. The pH of a plating bath for forming the CoNiFe film through electroplating is adjusted to 3.0 to 4.0 inclusive.

Abstract: A method of manufacturing a thin-film magnetic head allowing dimension control of the width of the magnetic pole and reduction of the time required for formation is provided. A layer of iron nitride formed by sputtering is selectively etched with the RIE to form a top pole tip. In this etching process with RIE, chlorine-type gas is selected as a gas seed for etching, and the process temperature is in a range of 50° C. to 300° C. Subsequently, using part of a first mask and a tip portion of the top pole tip as a mask, part of both the write gap layer and the second bottom pole are etched with the RIE similarly to the above process, to thereby form a magnetic pole. The etching conditions are optimized by performing the process with the RIE under the above conditions, so that both of the top pole tip and the magnetic pole can be formed with high precision, and that the time required for forming both of these elements can be significantly reduced.