Fabrication method of semiconductor device using epitaxial growth process

Claim 1

A fabrication method of a semiconductor device, said method comprising the steps of: (a) forming a first insulating film on a first single-crystal semiconductor layer of a first conductivity type; (b) selectively forming a first polycrystalline semiconductor film and a second insulating film on said first insulating film, respectively, said first insulating film being exposed through a first opening formed between opposing ends of said first polycrystalline semiconductor film and said second insulating film; (c) selectively removing said first insulating film using said first polycrystalline semiconductor film and said second insulating film as a mask, thereby forming a second opening greater in plan size than said first opening; (d) epitaxially grow a second single-crystal semiconductor layer of said second conductivity type on said first single-crystal semiconductor layer in said second opening; (e) removing said second insulating film to expose a part of said second single-crystal semiconductor layer; and (f) forming a third single-crystal semiconductor layer of said first conductivity type in or on said exposed part of said second single-crystal semiconductor layer to thereby produce a p-n junction therebetween; wherein a thickness of said second single-crystal semiconductor layer is defined by a height of said second opening.