| 摘要 |
PURPOSE:To prevent the deterioration of the quality of a crystal due to the detachment of steam from a pipe wall during crystal growth by sufficiently lowering the temperature of the wall of a reaction pipe even when steam is adsorbed to the wall of the reaction pipe and actually descending the steam pressure of steam. CONSTITUTION:A refrigerant cooling the wall of a reaction pipe is introuduced from an inlet 3 and discharged from an outlet 4 between the wall 1 of the reaction pipe and an outer pipe 2 surrounding the wall of the reaction pipe. A gas used for a reaction is introduced from an inlet 5, and a crystal growth reaction is executed on a substrate 10 placed on a substrate holder 7 heated by a heater 8 mounted into the reaction pipe surrounded by the wall 1 of the reaction pipe. The concentration of moisture in a growth gas atmosphere is kept in 2ppm or less by controlling the temperature of the wall of the reaction pipe, with which a raw material gas is in contact, at -70 deg.C oe lower. Accordingly, moisture on the inner wall of the reaction pipe adsorbing water molecules of steam in high concentration of 10ppm or higher at room temperature or a temperature close to room temperature is frozen. |
