Abstract: Techniques for fabricating integrated circuits having devices with gate oxides having different thicknesses and a high nitrogen content include forming the gate oxides at pressures at least as high as 2.0 atmospheres in an ambient of a nitrogen-containing gas. In one implementation, a substrate includes a first region for forming a first device having a gate oxide of a first thickness and a second region for forming a second device having a gate oxide of a second different thickness. A first oxynitride layer is formed on the first and second regions in an ambient comprising a nitrogen-containing gas at a pressure in a range of about 10 to about 15 atmospheres. A portion of the first oxynitride layer is removed to expose a surface of the substrate on the second region. Subsequently, a second oxynitride is formed over the first and second regions in an ambient comprising a nitrogen-containing gas at a pressure in a range of about 10 to about 15 atmospheres to form the first and second gate oxides.