| 摘要 |
PURPOSE:To realize diffusion processing without allowing migration of external air and influence thereof during movement by injecting the gas to the area near the region where the fork which loads diffusion boat and moves within the furnace core tube is located. CONSTITUTION:A boat 16 loading semiconductor substrates 15 is placed on a fork 17, the carrier gas is injected from a hole 19 and the diffusion gas is sent to a furnace core tube 11 from an apparatus 12. The boat 16 is inserted into the equally heated area in the tube 11 by means of a mechanism 18. The gas injected from the hole 19 shields the aperture of tube 11, preventing migration of external air thereinto. The diffusion gas, carrier gas and air migrating from the external side are exhausted 13. The fork 11 is drawn from the furnace core tube and heat processing is carried out to the substrates 15 on the boat 16. The carrier gas is injected from the hole 19 again after processing and the boat 16 is drawn. According to this constitution, increase of interface charge density generated at the interface of oxide film including external air and substrate can be prevented and change of characteristic can also be avoided. |
