Patent ID: 8574448
Filing Date: 2013-11-05
Classification: B08B,C23G,H01J,H01L

Abstract:
1. A cleaning method for cleaning an interior of a processing vessel by plasma-excited radicals of a cleaning gas under a first pressure, said method comprising the steps of: introducing a mixed gas of a diluting gas and said cleaning gas to a plasma generator under a second pressure lower than said first pressure; igniting plasma directly in said mixed gas at said second pressure by energizing said plasma generator; and increasing, after ignition of said plasma, a pressure inside said processing vessel to said first pressure from said second pressure while maintaining said plasma, wherein said step of increasing said pressure includes a phase in which a flow rate of said mixed gas is increased together with said pressure, wherein said plasma generator is a toroidal plasma generator, said toroidal plasma generator comprising a gas passage, said gas passage having a gas entrance and a gas outlet, forming a circuitous path, and having a coil wound around a part of said gas passage such that said coil winds around said gas passage at least twice, and wherein said energizing is conducted by feeding a current to said coil.