Patent ID: 6943764

Claim:
An active matrix display device comprising: a substrate having an insulating surface; a plurality of pixel electrodes arranged in a matrix form over said substrate; a plurality of switching elements operationally connected to said pixel electrodes, each of said switching elements comprising a first thin film transistor over said substrate; a display medium comprising an emissive material and capable of electrically changing luminous strength disposed at each of said pixel electrodes; and a driver circuit comprising a plurality of second thin film transistors over said substrate for driving said plurality of switching elements, wherein each of said plurality of second thin film transistors comprises a crystallized semiconductor layer, a gate insulating film adjacent to said crystallized semiconductor layer and a gate electrode adjacent to said gate insulating film, wherein channel forming regions of said first thin film transistor and said plurality of second thin film transistors have a same conductivity type, wherein said crystallized semiconductor layer has source and drain regions and at least one lightly doped region, and wherein said lightly doped region is formed by an ion doping method, using said gate electrode as a mask.