| 摘要 |
PURPOSE:To obtain a uniform ion beam in a wide range and to improve the durability of an ion source device by supplying the electrons generated from an electron generator into a plasma forming chamber and starting high-frequency discharge by said electrons. CONSTITUTION:A one-body hermetic vessel is constituted of the plasma forming chamber 1 and a processing chamber 2 and the inside thereof is evacuated to a vacuum state through a discharge port 4. CF4, etc., are introduced through a gas introducing port 5 into the vessel to a prescribed pressure. An electrode 6 for leading out the ion beam is constituted of the 1st grid 7 and the 2nd grid 8. A positive high voltage is first impressed to the 1st grid 7 and electric current is inputted to the electron generating source 15 to generate the electrons 14. The impressed voltage of the 2nd grid 8 is controlled to the ground potential in this stage and the electrons 14 are accelerated by the positive high voltage. The high-frequency power is then impressed to a high-frequency coil 9 to start high-frequency discharge, by which the plasma density is quickly increased and the sustaining high-frequency discharge is generated. A negative voltage is further impressed to the 2nd grid 8 and the input power source to the electron generating source 15 is decreased so that the operation is smoothly shifted to an ordinary ion beam etching operation state.
|
