Vertical gate semiconductor device and method for fabricating the same

摘要

A source region is formed by performing ion implantation plural times to diffuse an impurity from the upper surface of a semiconductor region toward a region far dawn therefrom and to increase impurity concentration in the vicinity of the upper surface of the semiconductor region, whereby the source region and a gate electrode are overlapped with each other surely. Thus, offset between the gate and the source is prevented and an excellent ohmic contact is formed between a source electrode and the source region.