| 摘要 |
PURPOSE:To improve the yield by causing the reaction gas to continuously flow out of an epitaxial growth apparatus simultaneously with stopping the supply for replacement of the reaction gas, thereby decreasing the pressure at the reaction gas supply means side for reducing the foreign bodies adhering to a wafer. CONSTITUTION:For replacing the reaction gas, a pump is operated to close valves 7, 1, 2 and open valve 8, evacuating a chamber 21. At this time, valves 1a, 2b open so that the gas flows to the evacuation side, and the pressure at the inlet side is kept at 0.1 kg/cm<2> or less. The valve 8 is closed, the valves 1, 2 are opened, the valves 1a, 2b are closed, and N2 is indroduced into the chamber. After the chamber is filled with N2, the contents of the chamber are replaced with H2 by valve operation, and the valve 7 is opened when the atmospheric pressure is reached. A wafer 1 is heated 9 through a supporting plate 2, with H2 as a carrier SiCl4 is fed, and it is mixed with clear H2 and fed into the chamber to perform vapor phase epitaxy. With this structure, since the introduction speed of the reaction gas can be made lower after vacuum evacuation of the chamber, the foreign bodies adhering to the wafer decrease, and the defects in the epitaxial layer decrease, thereby improving the yield. |
