| 摘要 |
PURPOSE:To obtain an amorphous thin film having an excellent electrical characteristic by conducting separately the decomposition of a film-forming material gas and the generation of a hydrogen radical and by adjusting effectively the density of the hydrogen radical. CONSTITUTION:A direct excitation optical CVD apparatus A and a hydrogen radical generator B which constitute this system are connected to each other by a reaction chamber 1. The pressure inside the reaction chamber 1 is reduced, a material gas is supplied from an inlet 7 and discharged from an outlet 8 at a fixed rate of discharge, and thus the pressure inside the reaction chamber 1 is set to be invariable constantly. On the other hand, a substrate 12 is kept at a prescribed temperature by operating a heater 6. Ultraviolet rays hnu for effecting optical CVD are passed through a cover 3 from a source 2 of generation thereof and introduced into the reaction chamber through a window 4, so as to decompose the material gas and to form a-SiGe:H. Meanwhile, hydrogen is supplied into a hydrogen radical forming chamber 9 through an introduction pipe 11 and a hydrogen radical is formed in the chamber. This hydrogen radical is so supplied into the reaction chamber that the density thereof is maintained at constant value in the chamber. In this way, an amorphous thin film having an excellent electrical characteristic can be obtained. |
