Patent ID: 8460954
Filing Date: 2013-06-11
Classification: G02F,H01L

Abstract:
1. A method of manufacturing a semiconductor device having a thin film transistor and a thin film diode on a same substrate, the method comprising: (a) forming a non-crystalline semiconductor film on a surface of said substrate, wherein said non-crystalline semiconductor film includes a first non-crystalline portion positioned in a region of the surface of said substrate in which the thin film transistor is to be formed and a second non-crystalline portion positioned in a region in which the thin film diode is to be formed, said second non-crystalline portion being thicker than said first non-crystalline portion; (b) obtaining a crystalline semiconductor film including a first crystalline portion, resulting from crystallizing said first non-crystalline portion of said non-crystalline semiconductor film, and a second crystalline portion, resulting from crystallizing said second non-crystalline portion and having a rougher surface than said first crystalline portion, by radiating a laser beam for crystallization on said non-crystalline semiconductor film; and (c) forming a first island of semiconductor layer, which is later to become an active region of the thin film transistor, and a second island of semiconductor layer, which is later to become an active region of the thin film diode, by patterning said crystalline semiconductor film, wherein said first island of semiconductor layer includes said first crystalline portion, and said second island of semiconductor layer includes said second crystalline portion, wherein said step (a) includes: (a1) forming a lower layer film made of non-crystalline semiconductor in the region of the surface of said substrate in which said thin film diode is to be formed; and (a2) forming an upper layer film made of non-crystalline semiconductor in such a way as to be in contact with a surface of said lower layer film in the region in which said thin film diode is to be formed and in the region in which said thin film transistor is to be formed, in order to obtain said non-crystalline semiconductor film including said lower layer film and said upper layer film, wherein said first non-crystalline portion includes said upper layer film and does not include said lower layer film, and said second non-crystalline portion includes said lower layer film and said upper layer film.