Mos device and method of fabricating the same

A MOS device comprising:

• an n-channel semiconductor device and a p-channel semiconductor device comprising an SOI substrate consisting of a supporting substrate, an insulation film, a semiconductor layer patterned in a plurality of islands, a gate oxide film formed on respective islands of the semiconductor layer, and a gate electrode formed on the gate oxide film across the semiconductor layer;
• said p-channel semiconductor device being provided with a first boundary film in a peripheral region of the semiconductor layer between the gate electrode and the semiconductor layer, and said n-channel semiconductor device being provided with a second boundary film, thinner than the first boundary film, in another peripheral region of the semiconductor layer between the gate electrode and the semiconductor layer;
• and
• said first boundary film and second boundary film are thicker than the gate oxide film;
• wherein the first boundary film is formed in a region surrounding an entire periphery of the semiconductor layer of the p-channel semiconductor device between the gate electrode and the semiconductor layer.

A MOS device comprising:

• an n-channel semiconductor device and a p-channel semiconductor device comprising an SOI substrate consisting of a supporting substrate, an insulation film, a semiconductor layer patterned in a plurality of islands, surrounded by a field oxide film, a gate oxide film formed on respective islands of the semiconductor layer, and a gate electrode formed on the gate oxide film across the semiconductor layer;
• said p-channel semiconductor device being provided with a first boundary film in a peripheral region of the semiconductor layer between the gate electrode and the semiconductor layer, and said n-channel semiconductor device being provided with a second boundary film, thinner than the first boundary film, in another peripheral region of the semiconductor layer between the gate electrode and the semiconductor layer;
• and
• said first boundary film and second boundary film are thicker than the gate oxide film.