Patent ID: 8482008
Filing Date: 2013-07-09
Classification: H01L

Abstract:
1. A transistor comprising: a substrate; an insulating film over the substrate; a gate electrode between the insulating film and the substrate; a crystalline layer over the insulating film; a buffer layer over the crystalline layer in a region corresponding to a channel region of the transistor; an insulating layer over the buffer layer and in registry with the buffer layer; source and drain electrodes over opposite sides of each of the buffer layer and the insulating layer; and n+ silicon film regions over the opposite sides of each of the buffer layer and the insulating layer and between the source and drain electrodes and the crystalline layer, wherein, the crystalline silicon film is formed by irradiating an amorphous silicon film with a light beam through a photothermal conversion layer and the insulating film to provide the amorphous silicon film with heat treatment, and the photothermal conversion layer is made of a material having (a) a sufficiently high laser beam absorption ratio, (b) a low thermal diffusion rate relative to the buffer layer crystalline layer, and (c) has a melting point that is sufficiently high so that the photothermal conversion layer is not altered by heat generated during the processing of crystallizing the amorphous silicon film.