GAS PIPING SYSTEM, CHEMICAL VAPOR DEPOSITION DEVICE, FILM DEPOSITION METHOD, AND METHOD FOR PRODUCING SiC EPITAXIAL WAFER

A run-vent mode gas piping system in which a plurality of gases are supplied to an inside of a reactor in which vapor deposition is performed, the gas piping system comprising:

• a plurality of supply lines through which the plurality of gases are fed individually,
• an exhaust line that leads from an exhaust port of the reactor to an exhaust pump,
• a run line which has one or a plurality of pipes which respectively branch from the plurality of supply lines to supply the plurality of gases to the reactor,
• a plurality of vent lines which respectively branch from the plurality of supply lines and are connected to the exhaust line, and
• a plurality of valves which are respectively provided at branch points of the plurality of supply lines, and switches between feeding a gas to the run line side and feeding a gas to the vent line side, wherein
• the plurality of vent lines are separated from each other until the vent lines reach the exhaust line, and an inner diameter of the exhaust line is greater than an inner diameter of each of the plurality of vent lines.