| 摘要 |
There is provided a method of fabricating a semiconductor device, including the steps of (a) sequentially forming an epitaxial layer and a first insulating film on a semiconductor substrate, (b) forming the epitaxial layer with a recess, (c) forming a gate insulating film on an inner wall of the recess, (d) forming a polysilicon film so that the recess is filled with the polysilicon film, (e) etching back the polysilicon film so that a gate electrode having a thickness smaller than a depth of the recess is formed in the recess, (f) oxidizing the gate electrode at its surface with the first insulating film being used as a mask, to thereby form a third insulating film on the gate electrode, (g) forming a base region at a surface of the epitaxial layer with the third insulating film being used as a mask so that the base region has a thickness smaller than a depth of the recess, the base region having an electrical conductivity different from that of the epitaxial layer, (h) forming a source region at a surface of the base region with the third insulating film being used as a mask, the source region having the same electrical conductivity as that of the epitaxial layer, (i) exposing the base and source regions with the third insulating film being used as a mask, and (j) forming a source electrode over the third insulating film, the base region, and the source region. The method makes it no longer necessary to carry out a step of using a photoresist mask for forming a gate electrode and a step of using a photoresist mask for forming a contact between a source electrode and a source region.
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