A new fabrication method for submicron trackwidth thin film heads

A new head structure suitable for submicron trackwidth writer and its fabrication method were described. The key features of the new head were to use the film thickness instead of the stripe width of the head core to define the recording trackwidth and a laminated dual-axis anisotropy back-core to improve the flux carrying efficiency in the head. The front gap of the head was fabricated by focused ion beam precision machining/deposition. A wall angle of 1 degrees was achievable for a gap milled in a 1 mu m-thick track-core. The dual-axis film, which consists of two uniaxial sandwiches with their easy axes orthogonally oriented, exhibited isotropic BH loops and isotropic high-frequency permeability after RFA. significant improvement of magnetisation response and Aux conduction of the dual-axis core after RFA were observed by SKEM examinations with the cores excited by an electromagnet at frequency of 0.5 MHz and by a single-turn coil at 10 MHz. Although the dual-axis film exhibited isotropic magnetic properties after RFA, SKEM observations indicate that the two uniaxial sandwiches in the dual-axis core behaved independently. The isotropic magnetic properties of the dual-axis films after RFA appear to be the average effect of the two uniaxial sandwiches. The high frequency flux conduction was more effective along the hard axis than along the easy axis. The effective flux conduction in the dual-axis core was attributed to the contribution of hard axis behaviour of each uniaxial sandwich. However, domain wall motion-type response was also observed in the dual-axis core. (C) 1999 Elsevier Science B.V. All rights reserved.