Semiconductor device with MIS capacitor and method of manufacturing the same.

摘要

@ A semiconductor device with a metal-insulator-semiconductor capacitor has:
a semiconductor substrate (11) having a predetermined conductivity type and serving as one electrode of the metal-insulator-semiconductor capacitor, the semiconductor substrate being provided with a trench (13) of a cross-sectionally rectangular shape which extends along a direction of thickness of the semiconductor substrate from a major surface thereof;a doped semiconductor layer (23A) formed along at least side wall surfaces of the trench, the semiconductor layer, which is formed by deposition and etching, being provided with an outer surface, starting to extend in a rounded shape (24A) from major surface portions of the semiconductor substrate and extending substantially parallel to the side wall surfaces of the trench, and a recess, which is defined by the semiconductor layer, having round corners (25) at the bottom;a dielectric insulating layer (27) formed on an exposed surface including the major surface of the semiconductor substrate and the outer surface of the semiconductor layer; anda conductive layer (29) formed on the insulating layer to bury trench and serving as the other electrode.