| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a thin-film transistor which is stable in controllability, high in reliability, superior in mass productivity, inexpensive, and applicable to liquid crystal display with a large screen and a built-in peripheral circuit. SOLUTION: A polysilicon film 3, a gate insulating film 4, and a gate electrode film 5 are successively laminated on a glass substrate 1 for the formation of a thin-film transistor, where a part of the gate insulating film 4 which does not comes into contact with the gate electrode film 5 is doped with unwanted impurities when the polysilicon film 3 is doped with impurities, by which the thin film transistor is deteriorated in stability and reliability. Then, the surface of the part doped with unwanted impurities is removed through etching, so as to ensure stability and reliability for the thin-film transistor. As a result, a part 5a of the gate insulating film 4, which comes into contact with the gate electrode film 5, is set thicker than a part 5b of the gate insulating film 4 which comes into no contact with the gate electrode film 5.</p> |
