US Patent 7307006 Method of manufacturing semiconductor device

It is an object of the present invention to provide a technology to manufacture a semiconductor sheet or a semiconductor chip with a high yield using a circuit having a thin film transistor. A manufacturing method for a semiconductor device comprises: attaching a flexible base material to an element layer x times (x is an integer number of 4 or more), wherein a thickness of a base material which is attached to the element layer (y+1)th (y is an integer number of 1 or more and less than x) time is the same or smaller than that of a base material which is attached to the element layer y-th (y is an integer number of 1 or more and less than x) time.