Patent ID: 8646168

Claim:
A method for manufacturing a magnetic write head, comprising: depositing a magnetic write pole material; depositing an under-layer material; depositing a dielectric hard mask over the under-layer; forming a photoresist mask over the under-layer; and performing a reactive ion etching to transfer the image of the photoresist mask onto the dielectric hard mask, wherein the reactive ion etching is performed in a chemistry comprising fluorine containing gases and He; wherein the reactive ion etching is performed in a reactive ion etching tool, and wherein a CF 4 gas is input into the reactive ion etching tool at a first gas flow rate and a CHF 3 gas is input into the reactive ion etching tool at a second gas flow rate, and wherein the ratio of the first gas flow rate to the second gas flow rate is adjusted to form the dielectric hard mask with straight side walls.