A method of controlling the thickness of gate oxides in an integrated CMOS process which includes performing a two-step gate oxidation process to concurrently oxidize and therefore consume at least a first portion of the cap layer of the NV gate stack to form a blocking oxide and form a gate oxide of at least one metal-oxide-semiconductor (MOS) transistor in the second region, wherein the gate oxide of the at least one MOS transistor is formed during both a first oxidation step and a second oxidation step of the gate oxidation process.