SEMICONDUCTOR DEVICE AND ITS FABRICATING METHOD

摘要

PROBLEM TO BE SOLVED: To obtain a semiconductor device having a trench structure in which breakdown voltage of the device is prevented from lowering by preventing concentration of field to the end corner part of a trench. SOLUTION: A trench 22 has a planar shape where the part 23 in the vicinity of its end is narrower than the body part 24 closer to the center. The part 23 in the vicinity of the end is formed shallower than the body part 24 by dry etching and the end corner part of the trench is rounded. Since the singular point of a gate oxide film or a gate electrode is eliminated at the end corner part of the trench, concentration of field to the end corner part of the trench is relaxed or eliminated and the breakdown voltage is prevented from lowering at the end corner part of the trench. COPYRIGHT: (C)2003,JPO