Patent ID: 7186315
Filing Date: 2007-03-06
Classification: H01J

Abstract:
1. A plasma treatment apparatus that carries out plasma treatment on an article, the plasma treatment apparatus comprising: a vacuum vessel that houses the article and into which a treatment gas is introduced; a lower electrode that is provided inside said vacuum vessel and onto which is placed the article; an upper electrode that is provided above said lower electrode in said vacuum vessel; and a high-frequency power source that supplies high-frequency electrical power; wherein a return current flows back to said high-frequency power source; wherein said high-frequency power source supplies the high-frequency electrical power to said lower electrode; wherein said upper electrode has an inside electrode part that is provided in a central part of said upper electrode, an outside electrode part that is provided surrounding said inside electrode part, an insulating part that is interposed between said outside electrode part and said inside electrode part, and a variable impedance part that is electrically connected between said inside electrode part and said outside electrode part; and wherein said variable impedance part changes inductance or capacitance thereof such that respective impedances in different frequency ranges are individually changed so as to change a value of return current in a high-frequency range among return currents corresponding to respective frequency ranges which flows back to said high-frequency power source via said inside electrode part without changing a value of return current in a low-frequency range.