US Patent 7745269 Semiconductor device and manufacture method thereof

An object is to provide an element structure of a semiconductor device for increasing an etching margin for various etching steps and a method for manufacturing the semiconductor device having the element structure. An island-shaped semiconductor layer is provided over an insulator having openings. The island-shaped semiconductor layer includes embedded semiconductor layers and a thin film semiconductor layer. The embedded semiconductor layers have a larger thickness than that of the thin film semiconductor layer.