Ultra-thin gate oxides are formed by exposing the upper surface of a substrate to a pulsed laser light beam in an atmosphere containing oxygen. Embodiments include exposing a silicon substrate to a pulsed laser light beam at a radiant fluence of 0.1 to 0.8 joules/cm2 for 1 to 10 nanoseconds to form a gate oxide layer having a thickness of 3 Å to 8 Å, e.g., 3 Å to 5 Å.