Patent ID: 8143170
Filing Date: 2012-03-27
Classification: H01L,Y10S

Abstract:
1. A method for manufacturing a semiconductor device, comprising the steps of: forming a first insulating film over a single crystal semiconductor substrate; irradiating the single crystal semiconductor substrate provided with the first insulating film with an accelerated ion, so that a fragile region is formed at a predetermined depth from a top surface of the single crystal semiconductor substrate; forming a first conductive film over the first insulating film; forming a second insulating film over the first conductive film; attaching the second insulating film to a base substrate, and performing a thermal treatment to separate the single crystal semiconductor substrate in the fragile region, so that a single crystal semiconductor layer is formed over the base substrate; forming a first resist mask at least over a region which forms a channel formation region of the single crystal semiconductor layer; selectively adding an impurity element having one conductivity type to a region of the single crystal semiconductor layer, which is not covered with the first resist mask; removing the first resist mask after adding the impurity element; forming a second conductive film over the single crystal semiconductor layer after removing the first resist mask; forming a second resist mask having a depression over the second conductive film; performing a first etching on the first insulating film, the first conductive film, the second insulating film, the single crystal semiconductor layer, and the second conductive film by using the second resist mask to expose at least the first conductive film; performing a second etching with accompanying a side-etching on a part of the first conductive film to form a pattern of a gate electrode layer; forming a third resist mask by making the second resist mask recede to expose a part of the second conductive film, which overlaps the depression of the second resist mask; and performing a third etching on the part of the second conductive film by using the third resist mask to form a source and drain electrode layers.