| 摘要 |
PURPOSE:To mix the reactive gas introduced into a liner tube in the upstream part of the liner tube, and also to throttle the gas flow above a substrate so as to obtain a uniform laminar flow by constituting a susceptor out of a liner tube in the shape of an inner tube when placing the substrate for crystal growth on the susceptor, and providing a minute gap at the side where the substrate is placed. CONSTITUTION:A conical liner tube 12, which is expanding in the direction of gas downstream, is provided in an inner chamber 11 surrounded by a quartz tube 10. That is, the cross section vertical to the axis of the liner tube 12 is constituted in a circle that the radius is large along the direction of an X axis being the gas flow direction. Moreover, on the side of the downstream of the liner tube 12, a conical susceptor 20 of barrel type is provided to cover it from upstream side. Moreover, the side of the susceptor 20 on which to place many sapphire substrates 50 is covered with the liner tube 12 small intervals apart. This way, the gap to the upper tube wall 24 of the liner tube 12 is 12mm at the upstream part of the substrate 50, and 4mm at the downstream part, and the reactive gas is made into a high speed and uniform laminar flow above the substrate 50. |
