Patent ID: 6909117
Filing Date: 2005-06-21
Classification: G02F,H01L

Abstract:
1. A semiconductor device comprising a plurality of thin film transistors formed over a transparent insulating substrate, each of said thin film transistors comprising: a semiconductor layer, a gate insulating film, and a gate electrode being laminated in order from a side near the transparent insulating substrate, and a source region and a drain region being formed in the semiconductor layer outside the gate electrode, wherein the gate electrode comprises a first layer gate electrode and a second layer gate electrode located over the first layer gate electrode wherein the first layer gate electrode extends beyond a side edge of the second layer gate electrode, wherein a first impurity region is formed in the semiconductor layer below the extending portion of the first layer gate electrode, wherein a second impurity region and the source region or the drain region are formed adjacent to each other from a side near the gate electrode in the semiconductor layer being the outside of a side edge of the first gate electrode, and wherein an impurity concentration of the first impurity region is higher than that of the second impurity region and lower than that of the source region or the drain region.