PRODUCTION OF THIN-FILM TRANSISTOR

摘要

PROBLEM TO BE SOLVED: To improve the boundary level of a boundary between a semiconductor film and a protective film by exposing the surface of the semiconductor film on the boundary therebetween in a plasma in which a specific gas is introduced, before the formation of protective film. SOLUTION: A metallic film made of Cr, etc., is formed on an insulation substrate 1 and a gate electrode pattern 2 is formed through a phorographic processing method. Next, a gate insulation film 3 and a semiconductor film 4 are formed, and the surface of the film 4 is exposed in a plasma which is formed by introducing either of He, Ne, Ar, Kr, N2 , and Xe. Or, at least two kinds out of H2 , Ne, Ar, Kr, N2 , and Xe are mixed to make a plasma, and the surface thereof is exposed therein, then a protective film is formed. The boundary level of a boundary between the semiconductor film and protective film is made higher than that before the irradiation of plasma, thereby reducing the conductivity and mobility of the semiconductor film in the boundary therebetween and making it to be inactive. A back-channel current flowing as leak current through the boundary therebetween of the thin-film transistor at the time of OFF state is reduced, and as a result the OFF-state current is reduced as well.