| 摘要 |
PURPOSE:To improve a durable life by forming the flange of a supporting tube of sintered Si3N4 or a base material having the same thermal expansion coefficient as that, and forming an Si3N4-coating layer on the flange to prevent an impurity from being sputtered. CONSTITUTION:A supporting tube 11 is concentrically formed outside a gas tube 14. The flange 11a contacted at least with a susceptor 12 of the tube 11 is composed of a sintered Si3N4 or a base material having the same thermal expansion coefficient as that. The flange 11a is coated with an Si3N4 coating layer. Then, when the flange 11a is mounted with a susceptor 12, SiC existed on the susceptor 12 is not reacted with the flange 11a even at the processing temperature of 1200 deg.C. Thus, it can prevent impurities from being sputtered to improve the durable life. |
