1. Field of the Invention
The present invention relates to a magnetic device, a perpendicular magnetic recording head performing the recording process of a perpendicular recording system, a magnetic recording system equipped with a perpendicular magnetic recording head, a method of forming a magnetic layer pattern, and a method of manufacturing a perpendicular magnetic recording head.
2. Description of the Related Art
As an application of a magnetic device provided with a magnetic layer, a thin film magnetic head to be equipped on a magnetic recording system such as a hard disk drive is widely used in the recent years. In the field of developing the thin film magnetic head, the recording density of a magnetic recording medium such as a hard disk (hereinafter referred to simply as a “recording medium”) is far improved, and a still further improvement in performance is required, and therefore the recording system is changed from a longitudinal recording system to the perpendicular recording system. The perpendicular recording system has the advantages that a high line recording density can be obtained, and the recording medium after recording is unsusceptible to the influence of thermal fluctuation.
The thin film magnetic head of the perpendicular recording system (hereinafter referred to simply as a “perpendicular magnetic recording head”) is provided with a thin film coil generating a magnetic flux, and a magnetic pole extending from an air bearing surface to rearward, and conducting the magnetic flux to the recording medium. In the perpendicular magnetic recording head, a recording medium can be magnetized by a magnetic field for recording (a perpendicular magnetic field), and therefore information can be recorded magnetically in the recording medium.
In the manufacturing process of the perpendicular magnetic recording head, it is necessary to narrow as much as possible a tip width (a trailing edge width) of the magnetic pole defining a recording track width in order to cope with an increase in surface recording density. As a method related to the method of narrowing the trailing edge width, there is known a method including the steps of: forming a photoresist pattern having an opening part; narrowing the opening part by forming an insoluble layer so as to cover the photoresist pattern; and then forming a plating layer at the opening part provided with the insoluble layer (for example, refer to Japanese Unexamined Patent Publication No. 2001-323393). There is also known a method including the steps of: forming a release layer and a photoresist pattern having an opening part in this order on a thin film; narrowing the opening part by forming an additional film so as to cover the photoresist pattern; and then forming a thin film pattern by etching the thin film by using, as a mask, the photoresist pattern and the additional film (for example, refer to Japanese Unexamined Patent Publication No. 2003-017474).
Besides the above-mentioned methods, there is known a method of forming a magnetic pole in the manufacturing process of a perpendicular magnetic recording head. That is, this method includes the steps of: forming a groove by etching an inorganic insulating film by using a photoresist pattern as a mask; removing the photoresist pattern; forming a stopper film and a magnetic film in this order so as to cover the inorganic insulating film; and then polishing the magnetic film until the stopper film is exposed (for example, refer to Japanese Unexamined Patent Publication No. 2002-092821). In this method, a main magnetic pole having a reverse trapezoidal cross section can be formed in the groove after polishing.
In the field of the latest device related manufacturing, ALD (atomic layer deposition) method is used as a film forming method extremely excellent in film thickness controllability (for example, refer to “ALD atomic layer deposition system,” Techscience Ltd., Internet<URL: http://techsc.co.jp/products/mems/ALD.htm>). The ALD method is capable of forming an oxide film, a nitride film, or a metal film considerably thinly and densely under high temperature condition of 150° C. or above, and it is used in the field of manufacturing where physical characteristics such as dielectric strength is strictly required. In the field of manufacturing a thin film magnetic head, the ALD method is used in the step of forming a reproducing gap of a reproducing head (for example, refer to the specification of U.S. Pat. No. 6,759,081).