Patent ID: 8169162
Filing Date: 2012-05-01
Classification: H01J,H05H

Abstract:
1. An apparatus for suppressing abnormal electrical discharge used for vacuum equipment which supplies power from a high-frequency power source into a plasma reaction chamber to generate plasma, the apparatus comprising, a power controller for controlling the high-frequency power source based on a deviation between a power command value and a power feedback value, and a cutoff controller for detecting reflected power or reflected wave voltage which is generated in at least any one of following timings; at a time of abnormal electrical discharge and during a transfer process to the abnormal electrical discharge within the plasma reaction chamber, and for cutting off a power supply from the high-frequency power source to the plasma reaction chamber, wherein, the cutoff controller comprises a first handling cutoff control and a second handling cutoff control, each having different time duration as a cutoff time, the first handling cutoff control exercises a control to cut off the high-frequency power source within a time duration which allows ions in the plasma reaction chamber to remain and an arcing element of minority arc to disappear, and the second handling cutoff exercises a control to cut off the high-frequency power source within a time duration which allows the ions to disappear, the ions of a majority arc at the time of abnormal electrical discharge.