Self-aligned trimmed pole

摘要

A trimmed upper pole piece for a magnetic write head is presented, said pole piece having a uniform width above and below a write gap layer and said pole piece being formed on a pedestal of uniform width projecting from a planar surface of a magnetic shield layer. Prior art methods of trimming pole pieces to a final width using ion-beam etches produce pole pieces with thickness differentials due to the etch resistant nature of the typical alumina write-gap filling material. The present pole piece uses NiCr, NiFeCr or Ru as write gap filling materials because they have an etch rate which is substantially equal to the etch rate of the other layers forming the pole piece and allow a uniform trimming to occur.