A trimmed upper pole piece for a magnetic write head, said pole piece
having a tapered profile that is widest at its trailing edge. Such a pole
piece is capable of writing narrow tracks with sharply and well defined
patterns and minimal overwriting of adjacent tracks. The necessary taper
is produced by using NiCr, NiFeCr, Rh or Ru as write gap filling
materials which have an etch rate which is substantially equal to the
etch rate of the other layers forming the pole piece and are highly
corrosion resistant. As a result, the write gap does not protrude to mask
the effects of the ion-beam etch used to form the taper.