Plasma processor apparatus and method, and antenna
First Claim
1. A plasma processor antenna adapted to be driven by power from an AC source, the antenna comprising first and second excitation terminals adapted to be powered by power from the source, a plasma excitation coil arranged to be energized by power coupled to said first and second excitation terminals via circuitry outside the antenna, the antenna having connections and reactances with values causing current flowing through the excitation terminals via the circuitry outside the antenna to be less than current flowing in a plasma excitation winding of the coil.
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Accused Products
Abstract
An antenna includes excitation terminals responsive to an RF source to supply an RF electromagnetic field to a plasma that processes a workpiece in a vacuum chamber. A matching network includes first and second portions respectively between the source and terminals and between the terminals and the antenna plasma excitation coil. In response to indications of impedance matching between the source and its load, currents flowing between (1) the first portion and the terminals and (2) the terminals and the coil are controlled so the latter exceeds the former. The indications control impedances of the first and second portions or the first portion impedance and the source frequency. The coil can include a transformer having a primary winding coupled to the excitation terminals and a multi-turn plasma excitation secondary winding.
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Citations
73 Claims
- 1. A plasma processor antenna adapted to be driven by power from an AC source, the antenna comprising first and second excitation terminals adapted to be powered by power from the source, a plasma excitation coil arranged to be energized by power coupled to said first and second excitation terminals via circuitry outside the antenna, the antenna having connections and reactances with values causing current flowing through the excitation terminals via the circuitry outside the antenna to be less than current flowing in a plasma excitation winding of the coil.
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24. An antenna for a plasma processor, the antenna being adapted to be driven by power from an AC source for exciting a plasma, comprising first and second excitation terminals, a coil including (a) a primary winding having opposite ends respectively coupled with the first and second excitation terminals, and (b) a secondary winding reactively coupled with the primary winding;
- and a capacitor having first and second opposite electrodes respectively connected in series with the secondary winding.
- View Dependent Claims (25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48)
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36. An antenna for a plasma processor, the antenna being adapted to be driven by power from an AC source for exciting a plasma, comprising first and second excitation terminals, a coil including (a) a primary winding having opposite ends respectively coupled with the first and second excitation terminals, and (b) a secondary winding reactively coupled with the primary-winding, the secondary winding including plural turns.
- 49. Apparatus for processing a workpiece with a plasma comprising a vacuum chamber arranged to process the workpiece with an AC plasma, an antenna for supplying an AC electromagnetic field to the plasma, an AC plasma excitation source, circuitry for coupling the AC source to excitation terminals of the antenna, the antenna including a plasma excitation coil for supplying a plasma exciting electromagnetic field to the plasma, and a controller for causing current flowing between the coupling circuitry and the excitation terminals to be less than current flowing in the coil.
- 68. A method of operating a vacuum plasma processor having a vacuum chamber including an AC plasma that processes a workpiece, the AC plasma being excited by an antenna that supplies an AC electromagnetic field to the plasma, the antenna being driven by power derived from an AC plasma excitation source and coupled to first and second excitation terminals of the antenna via coupling circuitry between the source and the terminals, the method comprising causing the current flowing in a plasma excitation coil of the antenna to exceed the current flowing between the coupling circuitry and the antenna excitation terminals.
Specification