| 摘要 |
PURPOSE: To prevent abrupt change in deposit composition by making an injection tube to be of small diameter over the first zone length while the tube diameter widened in one direction toward an outlet end part to form a wide outlet, and injecting the first reaction substance area at a low flow speed matching with that of gas flow. CONSTITUTION: With an injection tube 12 penetrating the first zone A in a reaction vessel 1, a volatile cadmium compound is injected into gas flow 38 and 36 at a position between a mercury supply source 3 and a substrate 29. The tube 12 has a small aperture (y) so that the cadmium compound passing the first zone is provided with high flow speed. Thus, the tube 12 has the small aperture (y) over the most part of the length of the first zone A, then gradually widened toward the outlet end part, so that a wide outlet is provided for the cadmium compound to be injected into the gas flow 36 and 38 at a low flow speed matching better with the flow speed of them at the above stated position. Thereby, significant change in deposit composition can be prevented. |
