Patent ID: 6624443
Filing Date: 2003-09-23
Classification: G02F,H01L

Abstract:
A display device being characterized in thata thin film transistor is formed over a substrate which constitutes the display device, the thin film transistor comprises: a semiconductor layer made of polysilicon which is comprised of a channel region, drain and source regions which are arranged at both sides of the channel region and are doped with impurity of high concentration, and at least one LDD region which is arranged between the drain region and the channel region and between the source region and the channel region or between the drain region and the channel region and are doped with impurity of low concentration, an insulation film which is formed over an upper surface of the semiconductor layer and sequentially decreases a film thickness thereof in a step-like manner as the insulation film is extended to the channel region, the LDD region, the drain and the source region or the drain region respectively, and a gate electrode which is formed over the channel region through the insulation film.