Si(0 0 1) surface oxidation by N2O

Ultra-thin homogeneous oxynitride films are prepared on Si(0 0 1). The Si surface is cleaned in UHV by heating (flashing) and is exposed to different pressures of N₂O at altered temperatures. Thus oxynitride layers of different thickness and different properties are grown depending on the N₂O pressure and the Si temperature. This is illustrated by a schematic diagram. The properties of the different oxynitride layers were studied by a combined photoemission electron microscopy (PEEM) and photoelectron spectroscopy (PES) investigation using highly monochromatic synchrotron radiation. The amount of oxygen and nitrogen incorporated in the oxynitride layers is determined from the PES measurements. The typical surface morphology for different preparation conditions is shown in PEEM images.