PRODUCTION OF SEMICONDUCTOR DEVICE

PURPOSE: To remove carbon films at the corners of a reaction chamber or in the upper part of a shower and in the lower part of a susceptor or in an exhausting part as well as in the side wall part of the reaction chamber by removing the carbon films accumulating in the reaction chamber through film formation by using a gas for oxidizing reaction. CONSTITUTION: In a cleaning step after carbon film formation, a pressure in a reaction chamber 1 is set to normal pressure and the inside of the chamber 1 is heated at about 100 deg.C by a heater 3 prepared on the bottom of a susceptor 2, then an O3 gas is introduced into the chamber 1 to oxidize the carbon films. When the O3 gas spreads sufficiently in the chamber 1, the carbon films are oxidized thereby and are turned into a gas such as SiO2 , etc., then they are exhausted. Therefore, the carbon films at the corners of the reaction chamber or in the upper part of a shower and in the lower part of the susceptor or in the exhausting part as well as in the side wall part of the reaction chamber are removed and almost all of carbon films are removed in the reaction chamber as a result. Thus, any particle is prevented from generation during film formation thereafter, resulting in carbon films having an excellent film quality.