MANUFACTURE OF LIQUID CRYSTAL DISPLAY UNIT

摘要

PROBLEM TO BE SOLVED: To enhance TFT characteristics by a method wherein an oxide nitride silicon film containing hydrogen is formed at least above a gate insulating film and then heat treated so as to hydrogenate an active layer beneath the gate insulating film. SOLUTION: An oxide nitride silicon film 10 is deposited on the whole surface of a channel region, a source region 5 and a drain region 6 of at least a TFT (a thin film transistor formed of a polysilicon layer) as well as a picture element part of a liquid crystal display unit. Next, the silicon film 10 is heat-treated in e.g. inert gas (N2, Ar, He, etc.), atmosphere to be hydrogenated. In such a constitution, when the polysilicon layer is hydrogenated using the oxide nitride silicon as a hydrogen supply source, the TFT characteristics (higher migration degree, lower threshold value) equivalent to the case of hydrogenation using a nitride silicon can be displayed.