| 摘要 |
PURPOSE:To reduce localized level density in a forbidden band safely and effectively to facilitate resistance control by providing a means with which a trace of gas selected from H2S, SO2, SF4 and SF6 is added to a given gas introduced into a vacuum chamber. CONSTITUTION:A means is provided by which at least one kind of gas selected from H2S, SO2, SF4 and SF6 is added to hydrogen gas used in many times as diluting gas for a given gas introduced (monosilane, diborane, phosphine, etc.) in a ratio of 0.5ppm-1% (volume ratio) against a monosilane amount. For example, when a ratio of H2S against monosilane required to make specific resistance of an amorphous silicon film formed 10<12>/cm or more necessary as a photosensitive material for electrophotography is examined, it is shown that sufficient specific resistance is obtained in the range of 0.5ppm or more and 1% or less in an additive amount of H2S (volume ratio) for both of specific resistance curves 21, 22 under a dark condition and an illuminated condition, thus allowing resistance control to be facilitated. |
