Patent ID: 7799649

Claim:
A method for manufacturing a semiconductor device, comprising: forming a silicon oxide masking layer over a silicon substrate in first and second active regions of a semiconductor device; patterning the silicon oxide masking layer to expose the substrate in the first active region and remain over the substrate in the second active region; subjecting the patterned silicon oxide masking layer and exposed substrate in the first active region to a first radical nitridation; following the first radical nitridation, subjecting the patterned silicon oxide masking layer and exposed substrate in the first action region to a first radical oxidation; following the first radical oxidation, removing the patterned silicon oxide masking layer, leaving the substrate exposed in the first active region and exposing the substrate in the second active region; following removal of the patterned silicon oxide masking layer, subjecting the exposed substrate in the first and second active regions to a second radical nitridation; and following the second nitridation, subjecting the exposed substrate in the first and second active regions to a second radical oxidation; wherein the first oxidation removes substantially all nitrogen atoms introduced into the patterned silicon oxide masking layer by the first nitridation; and whereby different thicknesses of silicon oxynitride dielectric are formed on the substrate in the first and second active regions.