Patent ID: 8217299
Filing Date: 2012-07-10
Classification: H01J,H05H

Abstract:
1. A method for applying power to a plasma chamber, comprising: delivering power from a power supply unit to the plasma chamber to ignite and sustain a plasma; detecting an arc in the plasma; diverting a plasma current associated with the arc away from the plasma by closing at a first time for a first time period a shunt switch within the power supply unit so as to extinguish the arc, the shunt switch being opened at a second time at the end of the first time period when there is no arc in the plasma and a plasma voltage is at an extinguished level; increasing the plasma voltage to reignite the plasma when the shunt switch is open; and pulsing the shunt switch with a plurality of pulses as the plasma voltage increases after the shunt switch is opened at the second time, the shunt switch being closed during each pulse to limit increases in the plasma voltage so that the plasma voltage does not exceed a voltage limit, and the shunt switch being open during an off-time between pulses to increase the plasma voltage to a reignition level that ignites the plasma, the shunt switch remains open after the plasma is ignited until another arc is detected to sustain the plasma.