APPARATUS FOR MANUFACTURING THIN FILM SEMICONDUCTOR

PURPOSE:To improve the quality of an amorphous semiconductor thin film by plus biasing the potential of a semiconductor thin film forming portion on an insulating substrate in case of manufacturing the thin film by a plasma CVD method and preventing positive ions coming from a plasma from colliding. CONSTITUTION:A transparent electrode 8 is applied on the surface of a glass substrate 5 placed on a lower electrode 3, and a conductive mask 9 for forming a film is superposed thereon. The mask 9 is electrically connected by a connecting conductor 10 with the electrode 3, and a high-frequency power source 11 and a DC power source 12 are inserted in series between upper and lower electrodes 2 and 3. Accordingly, the amorphous film forming portion of the substrate 5 becomes the same potential as the electrode 3. Thus, the amorphous film forming portion is plus biased to prevent positive ions during plasma during a glow discharge decomposing from colliding, thereby improving the quality of the obtained film.