Patent ID: 7569431

Claim:
A method of manufacturing a semiconductor device including the steps of: forming a first insulator film and a polycrystalline semiconductor film on a first principal surface of a single crystal semiconductor substrate of the first conductivity type; forming a window by removing part of the polycrystalline semiconductor film to expose part of the first insulator film; forming a second insulator film covering the polycrystalline semiconductor film and the exposed part of the first insulator film in the window; exposing part of the substrate in the window by removing the second insulator film and the first insulator film occupying the window; depositing a first conductivity type semiconductor film on the exposed part of the substrate in the window and on the second insulator film; forming in the first conductivity type semiconductor film a first semiconductor region of a first conductivity type and a second semiconductor region of the second conductivity type adjacent to the first semiconductor region as a region in contact with the substrate in the window; forming in the first conductivity semiconductor film a third semiconductor region of the first conductivity type on the opposite side of the first semiconductor region with the second semiconductor region positioned therebetween; depositing a third insulator film on the first semiconductor region, the second semiconductor region, and the third semiconductor region, and forming a contact hole in the third insulator film to expose part of the third semiconductor region and part of the second semiconductor region; forming a first electrode in contact with the exposed part of the third semiconductor region and the exposed part of the second semiconductor region through the contact hole; grinding a second principal surface of the substrate to form a fourth semiconductor region of the second conductivity along the ground second principal surface; and forming a second electrode in contact with the fourth semiconductor region.