摘要 |
An apparatus designed to increase the quality of a low-resistance semiconductor single crystal doped with an N-type volatile dopant to a high concentration and increase the production yield by controlling the pressure inside the furnace with good controllability. A vacuum line, a pressure control valve, and an open valve are newly added to the conventional semiconductor single crystal production apparatus. A controller controls the pressure control valve on the basis of a detection value of pressure detection means so as to obtain the desired low resistance value of the semiconductor single crystal. The open valve is controlled so that the open valve is opened in a case where the pressure inside the furnace detected by the pressure detection means reaches an abnormal value. |