PURPOSE: To obtain a chemical vapor growth apparatus by which an inessential reaction product film and an inessential reaction product are not produced inside a reaction chamber.
CONSTITUTION: While a semiconductor wafer 3 is being heated by using a heater 4, a first reaction gas B and O3 gas C are blown off to the surface of the semiconductor wafer 3. The inner wall of a chamber 1 is heated by using a heater 8. A second reaction gas D (ethylene C2H4 or the like) is blown off from reaction-gas blowoff ports 7 in directions which become distant form a wafer stage 2. Since O radicals are reacted with the second reaction gas D, a reaction product from is not produced. A reaction product does not adhere to the inner wall of the chamber 1 due to a thermal migration. As a result, it is not required to clean the inner wall surface of the chamber by stopping an apparatus periodically and to enhance the operation rate of the apparatus.
YUKI AKIMASA