Patent ID: 7262469
Filing Date: 2007-08-28
Classification: H01L

Abstract:
1. A semiconductor device, comprising: a thin film transistor including a semiconductor layer that includes a channel region, a source region, and a drain region; a gate insulating film provided on the semiconductor layer; and a gate electrode for controlling a conductivity of the channel region; wherein the gate electrode includes an inclined side surface and a bottom surface which is in contact with a surface of the gate insulating film; the semiconductor layer is a crystalline semiconductor layer formed through a melting/solidification process; a surface of the semiconductor layer includes a protruding portion located under the inclined side surface of the gate electrode, the protruding portion being formed through the melting/solidification process; the surface of the gate insulating film has an uneven surface corresponding to the protruding portion formed on the surface of the semiconductor layer; a cross-section of the gate electrode includes first and second opposing sides that are parallel to each other and a third side that is not parallel to any other side of the cross-section of the gate electrode; a side surface inclination angle of the gate electrode is larger than an inclination angle of the protruding portion of the semiconductor layer; and the side surface inclination angle of the gate electrode is an angle between a bottom portion of the inclined side surface of the gate electrode, which is in contact with the surface of the gate insulating film, and the bottom surface of the gate electrode.