Adjustable non-dissipative voltage boosting snubber network for achieving large boost voltages

Patent metadata

Field	Value
Publication number	US-2016336148-A1
Application number	US-201615222597-A
Country	US
Kind code	A1
Filing date	Jul 28, 2016
Priority date	Nov 1, 2012
Publication date	Nov 17, 2016
Grant date	—

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.

First claim

What is claimed is:

1 . 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.

2 . The pulsed DC power supply system of claim 1 , further comprising a third diode having an anode coupled to the second electrical node and a cathode coupled to the first electrical node, the third diode coupled in parallel with the first switch.

3 . The pulsed DC power supply system of claim 1 , wherein the voltage multiplier includes a capacitive element coupled between the first electrical node and the second rail.

4 . The pulsed DC power supply system of claim 3 , wherein the voltage multiplier includes two capacitive elements arranged to charge in series and discharge in parallel.

5 . The pulsed DC power supply system of claim 4 , wherein the voltage multiplier has two outputs: one coupled to the first electrical node; and one coupled to a second inductive element, the second inductive element coupled between the voltage multiplier and a third electrical node.

6 . The pulsed DC power supply system of claim 4 , wherein a first of the two capacitive elements is arranged to discharge through the first switch and the current limiter and the second of the two capacitive elements is arranged to discharge through (1) one of the outputs of the voltage multiplier, (2) the second inductive element, and (3) the second diode.

7 . The pulsed DC power supply system of claim 4 , wherein the voltage multiplier further includes at least a third and a fourth diode, the third diode coupled between the first and second capacitive elements, and wherein the fourth diode is arranged between the second rail and the third diode such that a cathode of the fourth diode is at a voltage of an anode of the third diode.

8 . The pulsed DC power supply system of claim 5 , wherein a controller closes the first switch when the controller determines that a voltage between the first and second rails has reached or exceeded a first threshold, V max , and opens the first switch when the controller determines that the voltage between the first and second rails has reached or fallen below a second threshold, V min .

9 . The pulsed DC power supply system of claim 5 , further comprising a second switch selectively coupling the second rail and the third electrical node.

10 . The pulsed DC power supply system of claim 9 , further comprising a voltage sensor coupled across the second of the two capacitive elements, wherein the second switch has a duty cycle that is a function of a voltage across the second of the two capacitive elements as measured by the voltage sensor.

11 . The pulsed DC power supply system of claim 1 , wherein the voltage-boosting circuit is part of a DC power supply coupled to and providing a first DC power to the first and second rails, such that a rail voltage exists across the first and second rails.

12 . The pulsed DC power supply system of claim 1 , wherein the voltage-boosting circuit is part of the switching circuit.

13 . The pulsed DC power supply system of claim 1 , wherein the first switch is selected from the group consisting of: insulated-gate bipolar transistors (IGBTs), bipolar junction transistors, and field effect transistors.

14 . The pulsed DC power supply system of claim 1 , wherein the voltage-boosting circuit increases a rail voltage V AB between the first and second rails by at least a factor of two when an impedance of a plasma load of the plasma substantially decreases.

15 . 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.

16 . The pulsed DC power supply system of claim 15 , further comprising a switching circuit coupled to the first and second rails and receiving the first DC power via the first and second rails and converting the first DC power to a first pulsed DC voltage configured for delivery to at least a first anodeless electrode of the plasma processing chamber

17 . The pulsed DC power supply system of claim 15 , further comprising a third diode having an anode coupled to the second electrical node and a cathode coupled to the first electrical node, the third diode coupled in parallel with the first switch.

18 . The pulsed DC power supply system of claim 15 , wherein the voltage multiplier includes a capacitive element coupled between the first electrical node and the second rail.

19 . The pulsed DC power supply system of claim 18 , wherein the voltage multiplier includes two capacitive elements arranged to charge in series and discharge in parallel.

20 . The pulsed DC power supply system of claim 19 , wherein the voltage multiplier has two outputs: one coupled to the first electrical node; and one coupled to a second inductive element, the second inductive element coupled between the voltage multiplier and a third electrical node.

21 . The pulsed DC power supply system of claim 19 , wherein a first of the two capacitive elements is arranged to discharge through the first switch and the current limiter and the second of the two capacitive elements is arranged to discharge through (1) one of the outputs of the voltage multiplier, (2) the second inductive element, and (3) the second diode.

22 . The pulsed DC power supply system of claim 19 , wherein the voltage multiplier further includes at least a third and a fourth diode, the third diode coupled between the first and second capacitive elements, and wherein the fourth diode is arranged between the second rail and the third diode such that a cathode of the fourth diode is at a voltage of an anode of the third diode.

Assignees

• Advanced Energy Ind Inc

Inventors

• Finley Kenneth W
• Walde Hendrik

Classifications

• H01J37/34

  operating with cathodic sputtering (H01J37/36 takes precedence {; methods of cathodic sputtering C23C14/34}) · CPC title

• H05H1/46

  using applied electromagnetic fields, e.g. high frequency or microwave energy (H05H1/26 takes precedence) · CPC title

• H01J37/32027 Primary

  DC powered · CPC title

• H01J37/32055

  Arc discharge · CPC title

• H01J37/32064 Primary

  Circuits specially adapted for controlling the arc discharge (for plasma torches H01H1/36) · CPC title