TRENCH MIS DEVICE HAVING ACTIVE TRENCH CORNER AND THICK-BOTTOM OXIDE, AND METHOD OF MANUFACTURING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a trench MOSFET low in capacitance between a gate and a drain, and excelling in high-frequency performance.

SOLUTION: The MIS device (MOSFET 100) includes: an N epi-region 116 adjacent to at least part of a bottom part of a trench 104 extending in a semiconductor substrate; and a P conduction type body region 112 adjacent to at least part of a sidewall of the trench. A first zone 106 of an oxide layer formed in the trench adjoins at least part of the N epi-region of the semiconductor device, and a second zone 110 adjoins at least part of the body region. The thickness of the oxide layer in the first zone is larger than that of the oxide layer in the second zone, the thickness of the oxide layer in a transition region 108 between the first and second zones gradually decreases from the first zone toward the second zone, and a p-n junction part 114 between the first and second regions terminates at the trench adjacent to the transition region of the oxide layer.

COPYRIGHT: (C)2009,JPO&INPIT