Cleaning method of ion source electrode

Abstract

PROBLEM TO BE SOLVED: To provide a cleaning method, which allows the removal of deposit on electrodes included in an extraction electrode system of an ion source at high speed over a wide area thereof. SOLUTION: The cleaning method comprises the steps of: supplying a cleaning gas 48 between a first electrode 11 and a second electrode 12, which are included in an extraction electrode system 10; and applying a voltage between the first and second electrodes 11 and 12 by a power source 60 for glow discharge to cause glow discharge 80 of the cleaning gas 48 between the electrodes 11 and 12 with a gas pressure between the first and second electrodes 11 and 12 kept higher than a gas pressure at the time of extracting an ion beam, instead of introducing an ionization gas into a plasma generating part 4 of an ion source 2 to extract an ion beam. COPYRIGHT: (C)2012,JPO&INPIT

Description

technical field [0001] The present invention relates to a cleaning method for removing deposits accumulated on the electrode surface constituting an ion source extracting electrode system. In addition, in this specification, when only an ion is called, it means a positive ion. Background technique [0002] When the operation of extracting the ion beam from the ion source is continued, deposits are deposited (attached) on the electrodes constituting the ion source extracting electrode system. If these deposits are left unattended, it may cause malfunctions such as abnormal discharge between electrodes. [0003] Therefore, as an example of a method of cleaning the ion source electrode, a cleaning method has been proposed in the past: supplying a rare gas into the plasma chamber instead of an ionizable gas, extracting an ion beam of the rare gas, and adjusting the gas flow rate and extraction voltage Either or both of them adjust the beam diameter of the ion beam, thereby cau...

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Problems solved by technology

[0005] In addition, the upper limit value of the current of the ion beam that extracts the plasma in the plasma chamber as an ion beam and irradiates each electrode is theoretically equivalent to the maximum ion beam current of the ion source, and it is only about several hundred mA at most. So it is difficult to remove the buildup at high speed

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