Abstract: A semiconductor fabrication process including a method of controlling the gate dielectric film thickness without adjusting the oxidation recipe. A sacrificial dielectric layer is formed on an upper surface of a semiconductor substrate. An oxidation inhibiting species is then introduced into the semiconductor substrate. The sacrificial dielectric layer is then removed from the substrate and the substrate is immersed into an oxygen bearing ambient maintained at a recipe temperature for a recipe duration. Preferably, the recipe temperature is in the range of approximately 500 to 800.degree. C. and the recipe duration is in the range of approximately 2 to 20 minutes. The final thickness of the gate dielectric film is adjusted by altering a concentration of the oxidation inhibiting species within the semiconductor substrate.