THIN FILM TRANSISTOR, MANUFACTURING METHOD THEREOF AND LIQUID CRYSTAL DISPLAY DEVICE

摘要

PROBLEM TO BE SOLVED: To suppress a change in the threshold voltage Vt of a thin film transistor. SOLUTION: A gate insulating film 4 contains SiO2 as its main component and the quantity of carbon in the insulating film 4 is set at 2×1019 cm-3 or more, whereby a thin film transistor, which has the high concentration film 4 and is little changed its threshold voltage Vt, is provided.