The present invention provides a thin film magnetic head in which a magnetic domain structure of a magnetic pole layer is controlled and fluctuation in recording magnetization caused by leaked magnetic flux generated by unintentional shift of a magnetic domain wall can be prevented. The interconnect structure of the invention achieves respective improved deviceinterconnect performance and affords a substantial dual damascene process window owing to the non-exposure of the OSG material to resist removal plasmas and because of the alternating inorganicorganic multilayer hardmask stack. The test architecture includes compare circuits that allow for comparison of test response data to be performed within the device. The orientations of the selected feature points are obtained by using a set of orientation calculating algorithms. A polygonal mirror is secured to the rotating shaft and coupled to the rotor frame through insert molding. This is sent for storage in the main memory of the computer at the location defined in the registers.