Heat treatment apparatus and method for processing substrates

摘要

A heat treatment apparatus includes a vertically disposed process tube defining a reaction chamber therein; a main heater for heating the reaction chamber, the main heater being disposed outside of the process tube; a boat for holding a plurality of wafers, the boat being loaded into and unloaded from the reaction chamber; and a boat rotating device for rotating the boat. The boat rotating device is provided with a rotatable hollow shaft assembly and a fixed shaft coaxially disposed inside the rotatable hollow shaft assembly. A sub-heater is attached to an upper end of the fixed shaft, and the boat and an insulating portion are disposed on the rotatable hollow shaft assembly.