MANUFACTURE OF THIN FILM TRANSISTOR

摘要

PURPOSE:To prevent picture elements and the like from becoming turbid in white, by using mixed gas, which does not include hydrogen, then using hydrogen based mixed gas, and forming a gate insulating layer by a CVD method. CONSTITUTION:A gate electrode 2 and a picture element electrode 3 are formed on a glass substrate 1. Then, a first silicon nitride film 91 is formed by a glow- discharge plasma CVD method by using mixed gas, which comprise silicon hydride, ammonia and nitrogen and does not include hydrogen. Then, a second silicon nitride film 92 is formed by the similar plasma CVD method by using hydrogen based mixed gas comprising silicon hydride, ammonia and hydrogen. Then an a-Si:H film is formed and patterned, and a semiconductor layer 5 is formed. Thereafter the first and second silicon nitride films 91 and 92 are patterned, and a gate insulating film 9 is obtained. Then, an Al film is formed and patterned, and a source electrode 6 and a drain electrode 7 are formed. Thus the TFT is completed.