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 &# 39 ; 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 .