PURPOSE: To prevent the generation of a metallic atom in a vessel and to form the glass film low in impurity on a substrate by arranging a heater mode of carbon for heating the substrate in a reaction vessel and also providing an induction coil in the outer peripheral of the vessel to generate plasma.
CONSTITUTION: The carbon-made heater 2 is arranged at a prescribed position inside the reaction vessel 1 made of glass and the substrate 3 is heated up to a prescribed temp. The inducotion coil 4 is arranged at a prescribed position on the outside surface of the reaction vessel 1, and the plasma is generated in the prescribed range adjacent to the substrate 3. Such a trouble that the metallic atom emitted from a metal-made electrode is incorporated into the glass film to be produced, is prevented before anythin happed because the electrode for plasma generation is not arranged in the reaction vessel. In such a way, the light loss of the obtained glass film is lessened.
ITO HIDEAKI
IKUNISHI SHIYOUGO
ONO KOICHI
