A method for fabricating a structure in a magnetic recording transducer is described. A trench having sidewalls converging in a corner and a depth is formed. A dielectric layer is deposited using physical vapor deposit (PVD). The dielectric layer thickness is not more than one-half of the trench depth. A remaining portion of the trench is unfilled by the dielectric layer and has a top and a bottom. A portion of the dielectric layer is plasma etched. The plasma etch removes the portion of the dielectric layer at the top of the trench at a first rate and removes the portion of the dielectric layer at the bottom of the remaining portion of the trench at a second rate less than the first rate. An additional dielectric layer is deposited, also using PVD. The plasma etch and additional dielectric layer depositing steps are optionally repeated until the trench is filled.