Patent attributes
An object is to provide a semiconductor device with improved reliability and for which a defect due to an end portion of a semiconductor layer provided in an island-shape is prevented, and a manufacturing method thereof. A structure includes an island-shaped semiconductor layer provided over a substrate, an insulating layer provided over a top surface and a side surface of the island-shaped semiconductor layer, and a gate electrode provided over the island-shaped semiconductor layer with the insulating layer interposed therebetween. In the insulating layer provided to be in contact with the island-shaped semiconductor layer, a region that is in contact with the side surface of the island-shaped semiconductor layer is made to have a lower dielectric constant than a region over the top surface of the island-shaped semiconductor layer.
