| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a thin-film transistor at a low cost which can restrain diffusion of impurities from a glass substrate to a semiconductor layer, and improve transistor characteristics, in particular the threshold voltage characteristic, a manufacturing method of the thin-film transistor, a transmission type liquid crystal display device capable of improving transmittance, and a manufacturing method of the liquid crystal display device. SOLUTION: This polycrystalline silicon thin-film transistor is provided with an insulating undercoat thin-film layer 32, formed on a glass substrate 31 by using a silicon oxinitride film, a semiconductor layer 35 which is formed on the thin-film layer 32 and has an active region 39, a source region 38s and a drain region 38d which are formed of a polycrystalline silicon film, a gate insulating film 36 formed on the semicondudor layer 38, and a gate electrode 37 arranged on the gate insulating film 36.</p> |
