Patent ID: 9378929
Filing Date: 2016-06-28
CPC Classification: C23C,H01J,H01L

Claim Text:
1. A plasma processing apparatus comprising: an evacuable vacuum vessel; a processing chamber disposed inside the vacuum vessel and having an interior configured to receive a sample to be processed and contain a plasma generated therein for processing; a gas supply unit to supply process gas for plasma generation to the processing chamber; a vacuum evacuation unit to evacuate the interior of the processing chamber to a depressurized condition; an antenna including a coil having opposing ends and being helically disposed outside of the vacuum vessel and a shield disposed outside of the coil, the shield being electrically connected to at least one of the opposing ends of the coil and electrically grounded; an RF power supply having a variable frequency to supply RF electric power within a predetermined frequency range, the RF power supply being electrically connected to the coil at an RF power supply position disposed between the opposing ends of the coil; and a frequency matching device to adjust at least one of the frequency of the RF power supply or a capacitance between the RF power supply position of the antenna and the ground to reduce or minimize reflected RF electric power; wherein the coil has an electrical length corresponding to an integral multiple of a wavelength of the predetermined frequency; and wherein the frequency matching device is configured to adjust the frequency of the RF electric power to generate the plasma inside the processing chamber while maintaining the capacitance between the RF power supply position of the antenna and the ground at a predetermined value.