US 7,476,898 B2
Thin film and manufacturing method of the same
Mitsuma Oishi, Kanagawa (Japan); and Masayuki Uehara, Kanagawa (Japan)
Assigned to NEC LCD Technologies, Ltd., Kawasaki, Kanagawa (Japan)
Filed on Apr. 13, 2005, as Appl. No. 11/104,424.
Claims priority of application No. 2004-118881 (JP), filed on Apr. 14, 2004.
Prior Publication US 2005/0230685 A1, Oct. 20, 2005
Int. Cl. H01L 21/84 (2006.01)
U.S. Cl. 257—72  [257/59; 257/E21.414; 257/E29.28; 257/E29.291; 438/149; 438/151] 12 Claims
OG exemplary drawing
 
1. A thin film transistor comprising:
an insulating substrate;
a gate electrode, a gate insulating film and first semiconductor film patterns, which are sequentially formed on the insulating substrate;
second semiconductor film patterns including a high density impurity, which are provided separately on the first semiconductor film patterns, and which face each other at both sides; and
a first electrode and a second electrode, each of which is formed on the second semiconductor film patterns which face each other,
wherein an area of the first semiconductor film patterns between the first electrode and the second electrode configures a channel portion of the thin film transistor; and
wherein the first semiconductor film patterns include a protruded portion protruding toward the outside from an end portion of the second semiconductor film patterns such that the protruded portion is extended from the end portion located on a remote side from the channel portion, and at least a part of the surface in the protruded portion of the first semiconductor film patterns having a rougher surface compared with a surface of the first semiconductor film of the channel portion.