Patent attributes
An object is to provide a method for manufacturing, with high yield, a semiconductor device having a crystalline semiconductor layer even if a substrate with low upper temperature limit. A groove is formed in a part of a semiconductor substrate to form a semiconductor substrate that has a projecting portion, and a bonding layer is formed to cover the projecting portion. In addition, before the bonding layer is formed, a portion of the semiconductor substrate to be the projecting portion is irradiated with accelerated ions to form a brittle layer. After the bonding layer and the supporting substrate are bonded together, heat treatment for separation of the semiconductor substrate is performed to provide a semiconductor layer over the supporting substrate. The semiconductor layer is selectively etched, and a semiconductor element is formed and a semiconductor device is manufactured.