We demonstrated a single-step method for fabricating sub-micron period surface relief gratings. The process consists of illuminating an acrylate-modified silica-titania sol-gel glass through a phase mask with an excimer laser at 193 nm. Since the material is self-processing, no further etching step is necessary to reveal the smooth sinusoidal profile. A Corrugation period of 0.56 mum and groove depth of 115 nm is reported. The resistance of the gratings to temperature or solvents makes them competitive for various applications in micro-optics.