Efficient energy recovery in a nanosecond pulser circuit
Some embodiments include a nanosecond pulser circuit. In some embodiments, a nanosecond pulser circuit may include: a high voltage power supply; a nanosecond pulser electrically coupled with the high voltage power supply and switches voltage from the high voltage power supply at high frequencies; a transformer having a primary side and a secondary side, the nanosecond pulser electrically coupled with the primary side of the transformer; and an energy recovery circuit electrically coupled with the secondary side of the transformer. In some embodiments, the energy recovery circuit comprises: an inductor electrically coupled with the high voltage power supply; a crowbar diode arranged in parallel with the secondary side of the transformer; and a second diode disposed in series with the inductor and arranged to conduct current from a load to the high voltage power supply.
1. A nanosecond pulser circuit comprising:
a high voltage power supply, wherein the high voltage power supply provides DC power with a voltage greater than 1 kV;
a plurality of switches electrically coupled with the high voltage power supply, the plurality of switches switch voltage from the high voltage power supply at high frequencies;
a transformer having a primary side and a secondary side, the plurality of switches electrically coupled with the primary side of the transformer; and
an energy recovery circuit electrically coupled with the secondary side of the transformer, the energy recovery circuit comprising:
an energy recovery inductor electrically coupled with the high voltage power supply; and
a diode disposed in series with the energy recovery inductor and arranged to restrict current flowing from the high voltage power supply through the energy recovery inductor to a load located on the secondary side of the transformer.
2. The nanosecond pulser circuit according to claim 1 , wherein the energy recovery inductor comprises an inductance greater than about 50 μH.
3. The nanosecond pulser circuit according to claim 1 , wherein the nanosecond pulser switches voltage from the high voltage power supply at frequencies of about 400 kHz.
4. The nanosecond pulser circuit according to claim 1 , wherein the nanosecond pulser circuit provides voltage greater than 5 kV to the load.
5. The nanosecond pulser circuit according to claim 1 , wherein the load comprises a capacitive load.
6. The nanosecond pulser circuit according to claim 1 , wherein the load comprises an electrode disposed in a plasma deposition chamber.
7. The nanosecond pulser circuit according to claim 1 , wherein the energy recovery circuit further comprises a high voltage switch in series with the diode and the energy recovery inductor.
8. The nanosecond pulser circuit according to claim 7 , wherein the high voltage switch switches voltages greater than 5 kV.
9. The nanosecond pulser circuit according to claim 1 , wherein the plurality of switches are arranged in a half-bridge or a full-bridge configuration.
10. A circuit comprising:
a high voltage storage capacitor;
a switching circuit coupled with the storage capacitator, the switching circuit outputs waveforms with voltages greater than 1 kV and with a frequencies greater than 1 kHz, the switching circuit comprising a plurality of switches arranged in a half-bridge or a full-bridge configuration;
a transformer having a primary side and a secondary side, the switching circuit electrically coupled with the primary side of the transformer; and
an energy recovery circuit electrically coupled with the secondary side of the transformer and the storage capacitor, the energy recovery circuit comprising:
an energy recovery inductor electrically coupled with the high voltage power supply having an inductance greater than 50 μH; and
a diode disposed in series with the energy recovery inductor and arranged to restrict current flowing from the high voltage power supply through the energy recovery inductor to a load located on the secondary side of the transformer.
11. The circuit according to claim 10 , wherein the energy recovery circuit comprises a crowbar diode arranged across the secondary side of the transformer.
12. The circuit according to claim 10 , wherein the stray resistance of the energy recovery circuit may be less than 1 ohm.
13. The circuit according to claim 10 , wherein the diode conducts current from a load through the energy recovery inductor to the high voltage power supply.
14. The circuit according to claim 13 , wherein the energy recovery circuit comprises a crowbar diode arranged across the secondary side of the transformer.
15. The circuit according to claim 10 , further comprising a bias compensation circuit that includes a bias compensation diode in parallel with the bias compensation switch; and a DC power supply arranged in series with the bias compensation diode and the bias compensation switch.
16. The circuit according to claim 10 , wherein the circuit does not include a matching network.
17. A plasma system comprising:
a plasma chamber;
an electrode disposed within the plasma camber;
a circuit disposed outside the plasma chamber comprising:
a high voltage storage capacitor;
a switching circuit coupled with the storage capacitator, the switching circuit outputs waveforms with voltages greater than 1 kV and with a frequencies greater than 1 kHz, the switching circuit comprising a plurality of switches arranged in a half-bridge or a full-bridge configuration;
a transformer having a primary side and a secondary side, the switching circuit electrically coupled with the primary side of the transformer; and
an energy recovery circuit electrically coupled with the secondary side of the transformer and the storage capacitor, the energy recovery circuit comprising:
an energy recovery inductor electrically coupled with the high voltage power supply having an inductance greater than 50 μH; and
a diode disposed in series with the energy recovery inductor and arranged to restrict current flowing from the high voltage power supply through the energy recovery inductor to the electrode.
18. The plasma system according to claim 17 , wherein the energy recovery circuit comprises a crowbar diode arranged across with the secondary side of the transformer.
19. The plasma system according to claim 17 , wherein the stray resistance of the energy recovery circuit may be less than 1 ohm.
20. The plasma system according to claim 17 , wherein the plasma system does not include a matching network.