Particle contamination control in a plasma afterglow
AssigneeUniversity of Iowa Research Foundation
InventorsJohn GOREE, Neeraj CHAUBEY
Life of this patent
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Abstract
Apparatus, methods, and systems are disclosed for controlling a charge on a particle in a plasma chamber and for controlling a lifting force on a particle in a plasma chamber. Controlling the lifting force, F˜QE, in a plasma afterglow, is achieved using a combination of two separate potentials during the afterglow. These potentials, one for controlling the charge on the panicle and one for controlling the lifting force, are applied to one or more electrodes of the plasma chamber at different times.
Claims14
A method for controlling a charge on a dust particle during a plasma afterglow, the method comprising:
- controlling a voltage signal between at least two of a plurality of electrodes included in a plasma chamber after a delay time after a power signal at the at least two of the plurality of electrodes is turned off, to control the charge.
7-23. (canceled)
A system for controlling a charge on a particle in a plasma chamber and for controlling a lifting force applied to the particle, the system comprising:
- a plurality of electrodes included in the plasma chamber;
- a power control signal generator;
- a power source coupled to the power control signal generator and to two of the plurality of electrodes;
- a first delay circuit coupled to the power control signal generator, the first delay circuit to control delivery of a charge control voltage signal to two of the plurality of electrodes, the charge control voltage signal to control the charge on the particle in the plasma chamber;
- and
- a second delay circuit coupled to the power control signal generator, the second delay circuit to control delivery of a lifting control voltage signal to two of the plurality of electrodes, the lifting control voltage signal to control a force on the particle in the plasma chamber.
A method for controlling a charge on a dust particle, the method comprising:
- delivering a radio frequency power signal to at least two of a plurality of electrodes included in a plasma chamber;
- and
- modulating the radio frequency power signal by turning the radio frequency power signal on and off to control the charge on the dust particle.
Dependencies are inferred from the claim text.