| 摘要 |
PURPOSE:To prevent the cracking and disconnection caused by the adhesion of a foreign material by forming a core glass film on a base, and then forming a silicone film on the core glass film within the same pressure-reduced reaction vessel. CONSTITUTION:A quartz base 3 is set in a reaction vessel 1, mass flow rate controllers 6a-6c are controlled to supply SiCl34 gas, GeCl4 gas and O2 from starting gas supplying sources 7a-7c. A high frequency voltage is applied to an induction coil 4 by a high frequency power source 5 to generate a plasma in the reaction vessel 1, and the gas is discharge-decomposed to accumulate a core glass layer on the quartz base 3 by reduced pressure plasma CVD method. Thereafter, the mass flow rate controllers 6a-6c are controlled to supply only SiCl4 gas into the reaction vessel 1. Then, SiCl4 is discharge-decomposed into Si and 2Cl2, and a silicone film is accumulated on the core glass film. Since it is not required to break the vacuum in the reaction vessel 1, therefore, the adhesion of a foreign material resulted from the breakage of the vacuum can be prevented. |
