Fabrication process for high track density yoke MR heads

A fabrication process was developed for a high track density yoke MR (magnetoresistive) head whose track width is determined by its front yoke thickness. The fabrication process, involving planarized front yoke formation, consists of the deposition process for a grooved yoke pattern with vertical side wall and a subsequent etch-back process with polystyrene polymer. Extraordinary recessed patterns, 3.5-μm deep, were almost completely planarized to less than 0.1 μm using these processes. Fabricated pattern-evaluation results indicate that CoZr system films are more suitable for use as a yoke material than NiFe films. Microstructure analyses reveal that the degradation in fabricated NiFe patterns is related to the structural change at the region near the grooved pattern side wall