Fabrication of thin film inductive heads with top core separated structure

A novel inductive head structure and process suitable for narrow track width have been developed based on a dry process. A top magnetic core of the head is separated into two parts, a pole tip and the rest core. This structure makes it possible to achieve smaller variation of the track width compared with a conventional head, because the pole tip can be formed at a lower step portion and a thinner photoresist pattern can be used as a masking for the etching of the pole tip part. The preferential etching ratio for a magnetic film to a masking layer was improved by using a double layer masking method. Reactive ion beam etching makes it possible to form fine and accurate pole tip patterns. The heads fabricated by using these methods revealed smaller variation of the track width and equivalent output level to a conventional head without any noise problem