| 摘要 |
PROBLEM TO BE SOLVED: To stably form an inorganic fluoride thin film such as MgF2 by the sputtering method. SOLUTION: A discharge electrode is set to the negative potential by applying the high frequency to the discharge electrode on which the raw material for a film consisting of inorganic fluoride is loaded from a high frequency power source, the plasma is generated above the raw material of the film by the power of the high frequency, the raw material of the film is sputtered by the positive ion while the temperature of the surface of the raw material of the film is raised by the plasma, at least a part of the raw material of the film is leaped in the molecular condition, and the raw material of the film in the molecular condition reaches a substrate to form a film on the substrate. The high frequency parameter to be applied to the discharge electrode is measured, and the output from the high frequency power source or the flow rate of the discharge gas to be introduced is controlled so that the measured high frequency parameter becomes a prescribed value. The plasma is kept in the constant condition by keeping the high frequency characteristic to affect the discharge electrode at the constant value, and the film forming speed and the quality of the film are kept to be constant. |
