COPLANAR TYPE THIN FILM TRANSISTOR, ITS MANUFACTURE, AND LIQUID CRYSTAL DISPLAY USING IT

摘要

PROBLEM TO BE SOLVED: To provide a TFT(thin film transistor) wherein electron mobility is increased, channel length is reduced, and self-alignment is perfect, and shorten the manufacturing process without using silicide. SOLUTION: A light shielding film 2 of Ta is formed on a glass substrate 1, and an SiO2 insulating film 3 covering the film 2 is formed, on which a film of I-type microcrystal silicon 4 is formed as a semiconductor layer and patterned in an island type. After a gate insulating film 5 is formed on the semiconductor layer, Al-Si alloy is sputtered on the film 5, and patterned in a gate electrode 6. The semiconductor layer is subjected to ion doping by using the gate electrode as a mask, and source.drain regions 7, 8 are formed. An interlayer insulating film 9 of Si3 N4 is formed. A contact hole penetrating the gate insulating film 5 and the interlayer insulating film 9 is formed by a patterning process and an etching process. A source.drain electrodes 11, 12 are formed by patterning the Al-Si alloy.