MANUFACTURE OF THIN FILM TRANSISTOR ARRAY

摘要

PURPOSE:To obtain a thin film transistor array whose threshold voltage and field effect mobility can be varied by specifying the temperature of a substrate when an amorphous silicon semiconductor layer is formed by a plasma CVD. CONSTITUTION:A gate electrode pattern 2 and a transparent electrode pattern 3 for a picture element electrode are formed on a transparent substrate 1. Then, a gate insulating film 4 made of insulating material such as silicon nitride, silicon oxide or tantalum oxide, an amorphous silicon film 5 and an n<+>-type amorphous silicon film 6 to be an ohmic contact layer are successively built up in this order from the bottom by a plasma CVD apparatus. When the amor phous silicon film 5 is formed by the plasma CVD in this process, the tempera ture of the substrate is maintained between 180 deg.C and 300 deg.C. With this constitu tion, the threshold voltage and the field effect mobility can be varied.