ARC RECOVERY WITHOUT OVER-VOLTAGE FOR PLASMA CHAMBER POWER SUPPLIES USING A SHUNT SWITCH

• US 20080203070A1
• Filed: 02/22/2007
• Published: 08/28/2008
• Est. Priority Date: 02/22/2007
• Status: Active Grant

• Current Assignee: AES Global Holdings Pte Ltd. (Advanced Energy Industries, Inc. (China))
• Original Assignee: Advanced Energy Industries Incorporated
• Inventors: Shilo, Vladislav V., Ilic, Milan, Huff, Robert Brian
• Granted Patent: US 8,217,299 B2
• Time in Patent Office: Days
• US Class Current: 219/121.57
• CPC Class Codes: H01J 37/32174 Circuits specially adapted for controlling the RF discharge
• CPC Class Codes: H01J 37/32623 Mechanical discharge control means
• CPC Class Codes: H05H 1/46 using applied electromagnetic fields, e.g. high frequency or microwave energy H05H1/26 takes precedence

Abstract

A system and method for over-voltage protection is described. In one embodiment of the invention, an apparatus includes an output port configured to deliver power to a plasma chamber to ignite a plasma. The apparatus also includes a shunt switch in parallel with the output port and a processor configured to receive an indicator of an arc in the plasma. The processor is configured to close the shunt switch for a period of time to divert current away from the arc. The processor is also configured to trigger a pulse of the shunt switch to limit a voltage of an increasing voltage condition associated with the arc.

Claims

1. An apparatus, comprising:

an output port configured to deliver power to a plasma chamber to ignite a plasma;

a shunt switch in parallel with the output port; and

a processor configured to receive an indicator of an arc in the plasma, the processor being configured to close the shunt switch for a period of time to divert current away from the arc, the processor being further configured to trigger a pulse of the shunt switch to limit a voltage of an increasing voltage condition associated with the arc.

2. The apparatus of claim 1, wherein the increasing voltage condition occurs during an arc recovery time period associated with the arc.

3. The apparatus of claim 1, wherein the increasing voltage condition is triggered when the shunt switch is opened after being closed for the period of time, the shunt switch is closed substantially at a beginning of the arc.

4. The apparatus of claim 1, wherein the pulse of the shunt switch is based on a pulse parameter value, the pulse parameter value includes at least one of a pulse width, a pulse period, a number of pulses, or an off-time.

5. The apparatus of claim 1, wherein the pulse of the shunt switch is based on a pulse parameter value, the processor is configured to calculate the pulse parameter value based on a plasma system parameter value, the plasma system parameter value includes at least one of an output inductance of a power supply unit, an output capacitance of the power supply unit, an output current of the power supply unit, or an output voltage of the power supply unit.

6. The apparatus of claim 1, further comprising a memory configured to store a pulse parameter value associated with the pulse.

7. The apparatus of claim 1, wherein the output port, shunt switch and processor are included in a power supply unit.

8. The apparatus of claim 1, wherein the increasing voltage condition is triggered when the shunt switch opens after a micro-arc timer expires.

10. The apparatus of claim 8, wherein the shunt switch is a first shunt switch, the power supply unit is a first power supply unit, the processor is configured to trigger a pulse of a second shunt switch associated with a second power supply unit, the second shunt switch is at least one of in series or substantially in parallel with the first shunt switch.

11. The apparatus of claim 8, wherein the power supply unit is a first power supply unit, the plasma system parameter value is associated with the first power supply unit, the processor is configured to detect a second power supply unit, the processor is further configured to calculate the pulse parameter value based on a plasma system parameter value associated with the second power supply unit.

12. The apparatus of claim 8, wherein the plasma system parameter value is a pulse width, the plasma system parameter value is a power level of a power supply unit.

13. The apparatus of claim 8, wherein the shunt switch is a first shunt switch, the processor is configured to calculate a pulse parameter value for a second shunt switch, the second shunt switch is in parallel with the first shunt switch.

14. The apparatus of claim 8, wherein the shunt switch is a first shunt switch, the processor is configured to trigger a pulse of a second shunt switch, the second shunt switch is in parallel with the first shunt switch, at least a portion of the pulse of the first shunt switch and at least a portion of the pulse of the second shunt switch are out of phase.

15. The apparatus of claim 8, wherein the power supply unit is a first power supply unit, the processor is configured to receive a plasma system parameter value associated with a second power supply unit.

16. The apparatus of claim 8, wherein the power supply unit is a first power supply unit, the pulse parameter value is a first pulse parameter value, the processor is configured to send a second pulse parameter value to a second power supply unit.

18. The method of claim 16, wherein the arc is a micro-arc.

19. The method of claim 16, wherein the pulsing includes pulsing according to a pulse parameter value, the pulse parameter value includes at least one of a pulse width, a pulse period, a number of pulses, or an off-time.

20. The method of claim 16, wherein the pulsing includes pulsing according to a pulse parameter value,

the method, further comprising:

calculating the pulse parameter value based on a plasma system parameter value.

21. The method of claim 16, wherein the power supply unit is a first power supply unit, the shunt switch is a first shunt switch,

the method further comprising:

receiving a plasma system parameter value from a second power supply unit, the plasma system parameter value is used to calculate at least one of a pulse parameter value for the first shunt switch or a pulse parameter value for the second shunt switch.

22. The method of claim 16, wherein the shunt switch is a first shunt switch, the pulsing includes pulsing out of phase with at least a portion of a pulse of a second shunt switch.

23. The method of claim 16, wherein the pulse of the shunt switch is based on a pulse parameter value, the processor is configured to calculate the pulse parameter value based on a plasma system parameter value, the plasma system parameter value includes at least one of an output inductance of the power supply unit, an output capacitance of the power supply unit, an output current of the power supply unit, or an output voltage of the power supply unit.

24. The method of claim 16, further comprising:

detecting at a third time whether the arc has been extinguished, the second time being after at least one pulse within the pulsing; and

closing the shunt switch at a fourth time when the arc has not been extinguished, the third time being after the second time.

9. An apparatus, comprising:

a shunt switch configured to divert current away from an arc in a plasma chamber, the shunt switch being configured to pulse according to a pulse parameter value, the pulse of the shunt switch limits a voltage of an increasing voltage condition associated with the arc; and

a processor configured to receive a plasma system parameter value, the shunt switch and the processor being associated with a power supply unit, the plasma system parameter value is associated with the power supply unit, the processor being configured to calculate the pulse parameter value based on the plasma system parameter value.

17. A method, comprising:

delivering power from a power supply unit to a plasma chamber to ignite and sustain a plasma;

detecting an arc in the plasma;

diverting a current associated with the arc away from the plasma at substantially a beginning of the arc by closing at a first time for a time period a shunt switch within the power supply unit, the shunt switch being opened at a second time at the end of the time period, an increasing voltage condition being triggered when the shunt switch is opened; and

pulsing the shunt switch, after the shunt switch is opened at the second time, to limit the voltage of the increasing voltage condition.