Embodiments described herein generally relate to methods for manufacturing flash memory devices. In one embodiment, the method includes generating a plasma comprising nitrogen-containing radicals in a remote plasma applicator, flowing the plasma comprising nitrogen-containing radicals into a processing region of the processing chamber where a semiconductor device is disposed, wherein the semiconductor device has a substrate comprising an oxide layer formed thereon, exposing an exposed surface of the oxide layer to the nitrogen-containing radicals, and incorporating nitrogen in the exposed surface of the oxide layer of the substrate.