ELECTROOPTICAL DEVICE, DRIVING SUBSTRATE FOR ELECTROOPTICAL DEVICE AND THEIR PREPARATION

摘要

PROBLEM TO BE SOLVED: To obtain a display panel with high quality image, high definition, narrow frame, high efficiency and large screen by constituting a part of a peripheral driving circuit of the first thin film transistor of a dual gate type having a gate part on each upper and lower part of a channel area of a single crystal silicon layer. SOLUTION: The photo-resist 2 is formed in a prescribed pattern in a TFT formation area, by using it as a mask, e.g. a F+ ion 3 of CF4 plasma is irradiated and plural steps 4 are formed in suitable shapes and dimensions on a gate insulation film by common lithography and etching. After removing photo-resist, single crystal silicon film 7 is made graphoepitaxial growth by catalytic CVD method on a full surface contg. the step 4. After depositing the single crystal silicon layer 7 on the substrate 1 in this way, a dual gate type electric field effect transistor (MOSFET) having the single crystal silicon 7 as a channel area and a top gate type MOSFET are made in a peripheral driving circuit part and in a display part respectively.