A method and non-volatile memory device are provided that are characterized by ion-implantation of impurities in the sidewalls of a first electrode. The inclusion of impurities in the sidewalls eliminates geometric abnormalities, referred to herein as a bird's beak, in the first electrode, which are caused by numerous oxidation processes being performed in the overall memory fabrication process. By eliminating these geometric abnormalities, thickening of the block oxide layer proximate the area of geometric abnormalities does not occurring, resulting in a memory device capable of efficiently programming and erasing data.