| 摘要 |
PROBLEM TO BE SOLVED: To shorten a trimming time, to suppress the reduction of a pole length as a result of shortening of the trimming time and to enlarge magnetic field strength by fixing an irradiating direction with an ion beam while trimming an upper magnetic pole and a lower magnetic pole by an ion milling method in a static state of a substrate and projecting ion particles to hit the trimming object closely targeted. SOLUTION: Trimming treatment of an upper layer part of a lower magnetic pole 8 is carried out by an ion milling method in a static state of a wafer substrate. First an ion beam is made incident on a surface of the lower magnetic pole 8 at a 50 deg.-90 deg. angle, thereby, trimming on the surface of the lower magnetic pole 8 is carried out efficiently and reduction of a pole length is suppressed. Then the trimming of an upper magnetic pole, strictly speaking trimming treatment to a side surface of a pole 16a is carried out. A tilt angle of a wafer is set to 50 deg.-80 deg. and the ion beam is made incident on the side surface of the pole 16a at the angle near to perpendicular to the side surface. Thus, the trimming of the pole 16a can be carried out efficiently.
|
