DEEP-TRENCH POWER MOSFET WITH AN R//O//N AREA PRODUCT OF 160 M OMEGA -mm**2.

A power MOSFET having an R//o//n area product of 160 m OMEGA multiplied by mm**2 (R//o//n equals 11 m OMEGA : BVdss equals 15 V, chip area 3. 8 mm multiplied by 3. 8 mm) which is approximately one-third of the lowest value believed reported is demonstrated. A recently developed deep-trench structure has contributed to such drastic reduction of the product. The advantages of the present structure are summarized as, low channel-resistance owing to the high-density packing capability, low spreading resistance in an epi-region due to the increased area of an accumulation layer formed along the sidewalls of the grooves, and completely eliminated parasitic JFET effect.