Thin-film transistor with suppressed off-current and Vth +B

摘要

A thin-film transistor (3, 5a, 5b and 5c) is covered with a first silicon nitride film (9) formed by an LPCVD method. A first silicon oxide film (6) is formed on the first silicon nitride film (9). A second silicon nitride film (7), i.e., passivation film which is formed by a plasma CVD method is provided on the first silicon oxide film (6). In addition, the thin-film transistor includes a semiconductor layer covering a gate electrode. The semiconductor layer includes source, drain and active regions. The active region preferably includes a smaller amount of fluorine than the gate electrode.