Abstract: A heat-treatment apparatus comprises a heat-treatment section for subjecting a heat-treatment to a wafer and a loading section for loading a wafer boat into and unloading it from the heat-treatment section. The loading section is connected to the heat-treatment section and includes in it a movable support member, a drive mechanism and a vertical base board as well as a load-lock chamber for maintaining the inside in vacuum. The movable support member supports a wafer boat. The movable support member is attached to a vertical base board so that it can move up and down. The drive mechanism is attached on the major surface of the vertical base board opposite to the surface facing the wafer boat. The drive mechanism drives the movable support to move up and down. The heat-treatment apparatus further comprises a wafer transfer section that includes an orientation flat alignment mechanism and a buffer stage disposed near the orientation flat alignment mechanism.

Abstract: A heat treatment apparatus used in the manufacturing of semiconductor devices and the like, for treating with a reaction gas substrates placed in a reaction tube of the apparatus. A support table is provided within the reaction tube, for supporting substrates during a treatment process, and is rotated during each treatment by a motor, via a shaft penetrating the reaction tube. That portion of the reaction tube which is penetrated by the shaft is provided with a journal bearing and a magnetic fluid seal member. The seal member is surrounded by an enclosing space which substantially separates the seal member from the reaction space within the reaction tube, the enclosing space and the reaction space communicating with each other via a narrow passage. During a heat treatment, a shield gas is supplied into the enclosing space, the pressure within the enclosing space being maintained at a higher level than that within the reaction space.