Power semiconductor device having semiconductor-layer-forming position controlled by ion implantation without using photoresist pattern, and method of manufacturing such power semiconductor device

摘要

A first insulator ( 710 ) having an opening within a central region ( 551 ) is formed on a main surface ( 61 S) of an epitaxial layer ( 610 ). Then, p-type impurities are ion implanted through the opening of the first insulator ( 710 ) and then heat treatment is carried out, thereby to form a p base layer ( 621 ) in the main surface ( 61 S). An insulating film is formed to fill in the opening and then etched back, thereby to form a second insulator ( 720 ) on a side surface ( 71 W) of the first insulator ( 710 ). Under conditions where the second insulator ( 720 ) is present, n-type impurities are ion implanted through the opening and then heat treatment is carried out, thereby to form an n⁺ source layer ( 630 ) in the main surface ( 61 S) of the p base layer ( 621 ).