| abstract |
The invention comprises a method of forming a semiconductor device is provided where a first gate insulator layer 26 is formed on an outer surface of semiconductor substrate 24. A mask body 28 is formed to cover portions of the insulator layer 26. The exposed portions of the layer 26 are subjected to a nitridation process to form a nitride layer 30. A second oxidation process forms a thick gate oxide layer 32. The nitride layer 30 inhibits the growth of oxide resulting in a single integrated device having gate insulator layers having two different thicknesses such that high voltage and low voltage transistors can be formed on the same integrated circuit. |