Metal oxide patterns with planar surface

A method of fabricating a magnetic metallic pattern on a substrate adapted for use with thin film recording heads comprising the steps of:

• a. forming a continuous, non-conductive, non-magnetic layer of a first material on said substrate;
• b. forming a continuous layer of a second material on said first material layer, said second material being an anodizable metal selected to be insoluable in an etchant of said first material;
• c. forming a photoresist layer on said second material layer in a negative pattern with respect to the desired metallic pattern;
• d. removing the exposed areas of said second material to expose said first material;
• e. plasma etching the exposed areas of said first material to define a cavity having relatively vertical side walls;
• f. removing any remaining portions of said second material layer;
• g. depositing a layer of said second material on said first material layer such that the thickness of said second material on the vertical side walls of said cavity is less than the thickness of the remainder of said second material layer;
• h. soft anodizing said second material layer to a depth sufficient to anodize the portions of said second material formed on said vertical side walls;
• i. dissolving the soft anodized portions of said second material such that the portions of said second layer formed on said side walls of said cavity are fully removed thereby electrically isolating the portions of said second material at the bottom of said cavity from the remaining portions of said second material located on the top of said first material;
• j. hard anodizing the exposed surface of said portions of said second material located on the top of said first material;
• k. removing the portion of said second material remaining in the bottom of said cavity;
• l. forming a continuous layer of said magnetic metallic material by sputtering such that said cavity is filled, and a relatively thin layer of said metallic material is defined adjacent the top edges of said cavity;
• m. removing the upper surface of said magnetic metallic material to a depth sufficient to expose said second material adjacent the top edges of the cavity;
• and
• n. dissolving said second material such that said magnetic metallic material deposited directly thereon is released from said first material whereby a metallic pattern having vertical side walls is formed in said cavity, with the top surface thereof being co-planar with the top surface of the remaining first material.