Adjustable non-dissipative voltage boosting snubber network for achieving large boost voltages
AssigneeAdvanced Energy Industries, Inc.
InventorsKenneth W. Finley, Hendrik Walde
Life of this patent
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Abstract
This disclosure describes a non-dissipative snubber circuit configured to boost a voltage applied to a load after the load's impedance rises rapidly. The voltage boost can thereby cause more rapid current ramping after a decrease in power delivery to the load which results from the load impedance rise. In particular, the snubber can comprise a combination of a unidirectional switch, a voltage multiplier, and a current limiter. In some cases, these components can be a diode, voltage doubler, and an inductor, respectively.
Claims32
A pulsed DC power supply system configured to provide pulsed DC power to a plurality of anodeless electrodes of a plasma processing chamber, the pulsed DC power supply comprising:
- a switching circuit coupled to first and second rails and receiving a first DC power via the first and second rails and converting the first DC power to a first pulsed DC voltage for delivery to at least a first anodeless electrode of a plasma processing chamber;
- and
- a voltage-boosting circuit coupled between the first and second rails, the voltage-boosting circuit comprising:
- a first diode coupled between the first rail and a first electrical node, an anode of the first diode being at a voltage of the first rail;
- a voltage multiplier coupled between the first electrical node and the second rail;
- a current limiter coupled between the first rail and a second electrical node;
- a first switch selectively coupling the first electrical node and a second electrical node;
- and
- a second diode coupled between the second rail and the second electrical node, an anode of the second diode being at a voltage of the second rail.
A pulsed DC power supply system configured to provide pulsed DC power to a plurality of anodeless electrodes of a plasma processing chamber, the pulsed DC power supply comprising:
- a DC power supply coupled to and providing a first DC power to a first and second rail, such that a rail voltage exists across the first and second rails;
- a voltage-boosting circuit coupled between the first and second rails, the voltage-boosting circuit comprising:
- a first diode coupled between the first rail and a first electrical node, an anode of the first diode being at a voltage of the first rail;
- a voltage multiplier coupled between the first electrical node and the second rail;
- a current limiter coupled between the first rail and a second electrical node;
- a first switch selectively coupling the first electrical node and a second electrical node;
- and
- a second diode coupled between the second rail and the second electrical node, an anode of the second diode being at a voltage of the second rail.
A method of operating a voltage-boosting circuit arranged between a first and second rail carrying DC current to a switching circuit that converts DC current on the first and second rails to a pulsed DC voltage and provides the pulsed DC voltage across a plasma load of a plasma processing chamber, the method comprising:
- providing a voltage-boosting circuit coupled between the first and second rails, the voltage-boosting circuit comprising:
- a first diode coupled between the first rail and a first electrical node, an anode of the first diode being at a voltage of the first rail;
- a voltage multiplier coupled between the first electrical node and the second rail;
- a current limiter coupled between the first rail and a second electrical node;
- a first switch selectively coupling the first electrical node and a second electrical node;
- and
- a second diode coupled between the second rail and the second electrical node, an anode of the second diode being at a voltage of the second rail;
- and
- maintaining the switch in an off state until charging of the capacitive element causes a voltage across the capacitive element to be at least twice a process voltage for the plasma.
Dependencies are inferred from the claim text.