Semiconductor device and method of manufacturing the same

A method of manufacturing a semiconductor device, comprising:

• forming a first insulating film on a semiconductor substrate;
• forming a semiconductor layer on the first insulating film;
• etching the semiconductor layer;
• oxide film forming that forms an oxide film on the etched semiconductor layer;
• p-type impurity implanting that implants p-type impurities into the semiconductor layer through the oxide film;
• first n-type impurity implanting that selectively implants n-type impurities into the semiconductor layer;
• and
• forming a second insulating film on the semiconductor layer,
• in the p-type impurity implanting, the p-type impurities being implanted so that a concentration peak of the implanted p-type impurities is located in a non-boundary region between a first boundary region that is a boundary region of the semiconductor layer with the first insulating film and a second boundary region that is a boundary region of the semiconductor layer with the second insulating film,
• the method further comprising second n-type impurity implanting that implants n-type impurities having a lower concentration than the concentration of the p-type impurities, into at least the first boundary region of the semiconductor layer.