| 摘要 |
PURPOSE:To prevent the adhesion of silicon to the umbrella of a gas nozzle and the generation of the defect of a wafer by providing the umbrella which has the circulating route of a gas for vapor phase growth before spouting inside and is made the reflection surface of the gas after spouting at the top of the gas nozzle. CONSTITUTION:A quartz gas nozzle 36 is provided at the upper center of a heating table 32 and the gas nozzle 36 has a dual pipe construction of inner pipe 36a and outer pipe 36b. Plural gas nozzles 37, 37... are provided on the side wall of the outer pipe 36b and an umbrella 38 is provided at the top of the outer pipe 36b. The umbrella 38 has a circulating route A which enables a gas for vapor phase growth to circulate in the umbrella 38 and an aperture 39 is provided at the top of the inner pipe 36a. Around the nozzle 36 is made a high temperature of more than 1,000 deg.C by the radiation heat from the heating table 32 but the circulation of normal temperature hydrogen gas and a gas for vapor phase growth in the umbrella 38 of the gas nozzle 36 has cooling effect and the umbrella 38 is made a comparatively low temperature. This prevents the adhesion of silicon to the umbrella 38 even if the gas for vapor phase growth is thermally decomposed. |
