DIFFUSION DEVICE

PURPOSE:To prevent a semiconductor wafer from being contaminated owing to the atmosphere without lowering an installation throughput capacity by providing a reaction chamber for high temperature diffusion and a furnace body portion for heating the reaction c chamber, at least one of them being made movable, and both being made free to be inserted and drawn. CONSTITUTION:A furnace body portion 1 and a reaction chamber 2 are individually heated to predetermined heating temperature. A semiconductor wafer 3 is housed in the reaction chamber 2 at a room temperature at a position separated from the furnace body section 1, and thereafter the reaction chamber 2 is evacuated and supplied with predetermined gas. Further, the reaction chamber 2 is inserted into the furnace body portion 1 and heated by the same of diffusion processing. Once the diffusion processing is completed, the reaction chamber 2 is drawn out of the furnace body portion 1, and the reaction chamber 2 is lowered in the temperature nearly to the room temperature keeping predetermined gas flowing into the reaction chamber 2, and the semiconductor water 3 is taken out from the reaction chamber 2. Perspective operations in the reaction chamber 2 can be done at satisfactorily low temperature without lowering installation throughput capacity, for preventing the semiconductor water 3 from being contaminated by the atmosphere.