Patent ID: 8828248

Claim:
A method of making a write pole for a perpendicular magnetic recording write head, comprising: forming a photoresist mask over a dielectric hard mask layer of a stack such that the photoresist mask covers a first portion of the dielectric hard mask layer and leaves a second portion exposed, wherein the stack comprises: a layer of magnetic material formed over a substrate; a layer of non-magnetic material formed over the layer of magnetic material; a polymeric underlayer formed over the layer of non-magnetic material; and the dielectric hard mask layer formed over the polymeric underlayer; performing a first reactive ion etch process to remove the exposed second portion of the dielectric hard mask layer such that a portion of the polymeric underlayer is exposed and a dielectric hard mask is formed, wherein a first portion of the first reactive ion etch process comprises exposing the second portion of the dielectric hard mask layer to an etching gas comprising CF 4 and CHF 3 , wherein a ratio of CF 4 to CHF 3 in the first portion is between about 1.3 and about 2, wherein a second portion of the first reactive ion etch process uses an etching gas comprising CF 4 , and CHF 3 , and wherein a gas flow ratio of CF 4 to CHF 3 in the second portion is between about 0.3 to 0.8; and performing a second reactive ion etch process to remove the exposed polymeric underlayer to expose the layer of non-magnetic material.