RADIO FREQUENCY POWER DELIVERY SYSTEM

• US 20080179948A1
• Filed: 02/01/2008
• Published: 07/31/2008
• Est. Priority Date: 10/31/2005
• Status: Abandoned Application

• Current Assignee: MKS Instruments Incorporated
• Original Assignee: MKS Instruments Incorporated
• Inventors: Barskiy, Yevgeniy, Tian, Feng, Nagarkatti, Siddharth P., Bystryak, Ilya
• Application Number:
  US12/024,734
• Publication Number:
  US 20080179948A1
• Time in Patent Office: Days
• US Class Current: 307/18
• CPC Class Codes: H01J 37/32082 Radio frequency generated discharge H01J37/32357, H01J37/32366, H01J37/32394 and H01J37/32403 take precedence
• CPC Class Codes: H01J 37/32183 Matching circuits
• CPC Class Codes: H03F 1/565 using inductive elements
• CPC Class Codes: H03F 2200/321 Use of a microprocessor in an amplifier circuit or its control circuit
• CPC Class Codes: H03F 2200/387 A circuit being added at the output of an amplifier to adapt the output impedance of the amplifier
• CPC Class Codes: H03F 2200/391 the output circuit of an amplifying stage comprising an LC-network
• CPC Class Codes: H03F 2200/393 A measuring circuit being coupled to the output of an amplifier
• CPC Class Codes: H03F 2200/451 the amplifier being a radio frequency amplifier
• CPC Class Codes: H03F 3/195 in integrated circuits
• CPC Class Codes: H03F 3/20 Power amplifiers, e.g. Class B amplifiers, Class C amplifiers H03F3/26 - H03F3/30 take precedence
• CPC Class Codes: H03H 7/40 Automatic matching of load impedance to source impedance

Abstract

A system and method are provided for delivering power to a dynamic load. The system includes a power supply providing DC power having a substantially constant power open loop response, a power amplifier for converting the DC power to RF power, a sensor for measuring voltage, current and phase angle between voltage and current vectors associated with the RF power, an electrically controllable impedance matching system to modify the impedance of the power amplifier to at least a substantially matched impedance of a dynamic load, and a controller for controlling the electrically controllable impedance matching system. The system further includes a sensor calibration measuring module for determining power delivered by the power amplifier, an electronic matching system calibration module for determining power delivered to a dynamic load, and a power dissipation module for calculating power dissipated in the electrically controllable impedance matching system.

Claims

1. A hybrid system for delivering power to a load, comprising;

a power converter system;

an outer loop coupled to the power converter system that provides a gain-bandwidth and a phase margin for substantially maintaining stability of output power; and

an inner loop coupled to the power converter system for compensating for nonlinearities in the power converter system.

2. The system of claim 1, wherein the outer loop is an analog control loop.

3. The system of claim 2, wherein the inner loop is a digital control loop.

4. The system of claim 3, wherein the analog control loop includes an analog control, and an output conditioning block for regulating output power.

5. The system of claim 4, wherein the digital control loop includes:

an analog-to-digital converter for converting an analog measurement taken at the power converter to a digital measurement for determining a digital current set point;

a digital control to output the digital current set point for determining a power width modulation signal; and

a digital-to-analog converter for converting the digital current set point to an analog current set point for determining the power width modulation signal for regulating output power.

6. The system of claim 5, wherein the analog control loop outputs the power width modulated signal based on the analog current set point and an analog measurement taken at the power converter system for regulating output power.

7. The system of claim 5, wherein the power converter system includes a DC source, and a RF power amplifier.

8. The system of claim 7, wherein a RF power measurement taken at the RF power amplifier is digitized by the analog-to-digital converter to produce a digital RF power measurement for determining a pulse width modulation signal for regulating output power.

9. The system of claim 8, wherein the digital control outputs a digital current set point for determining the pulse width modulation signal for regulating output power.

10. The system of claim 9, wherein the digital current set point is converted to a analog current set point for determining the pulse width modulation signal for regulating output power.

11. The system of claim 10, wherein the analog control loop outputs the power width modulated signal based on the analog current set point and an analog current set point measurement taken at the DC source for regulating output power.

12. A digital and analog hybrid method for delivering power to a load, comprising:

providing a gain-bandwidth and a phase margin for substantially maintaining stability of an output power; and

compensating for nonlinearities in the in the output power.

13. The method of claim 12, further comprising:

measuring delivered RF power signal;

converting the measured delivered RF power from an analog signal to a digital delivered RF power signal; and

determining a digital current set point from the digital delivered RF power signal and a RF power set point;

14. The method of claim 13, further comprising:

converting the digital current set point from a digital signal to an analog current set point signal;

measuring DC current at a power supply; and

determining a duty cycle command from the analog current set point signal and the DC current;

15. The method of claim 14, further comprising:

determining a pulse width modulation signal from the duty cycle command; and

regulating the power supply with the pulse width modulation signal.

20. The system of claim 14, wherein the slave power system includes:

a DC source for supplying power;

a RF power amplifier with phase compensation for supplying power with a substantially constant phase;

a VI probe for monitoring the phase of the RF power amplifier output; and

an electronic matching system for matching the phase of the RF power amplifier and the load.

22. The system of claim 14, wherein the master power system is 180 degrees out of phase with the slave power system.

23. The system of claim 14, wherein the master power system controls two or more slave power systems to deliver power with an amplitude and phase equal to the amplitude and phase of the master power system to two or more loads.

16. A system for delivering synchronous power, comprising:

a master power system having a maximum power that delivers power to a first dynamic load; and

a slave power system having a maximum power equal to the maximum power of the master power system and delivers power having a phase equal to a phase supplied by the master power system to a second dynamic load.

17. The system of claim 16, wherein the master power system includes:

a DC source for supplying power;

a RF power amplifier with phase compensation for supplying power with a substantially constant phase;

a VI probe for monitoring the phase of the RF power amplifier output; and

an electronic matching system for matching the phase of the RF power amplifier and the load.

18. The system of claim 17, wherein the output the master power system delivers to the load depends on the output of the VI probe.

19. The system of claim 16, wherein the RF power amplifier with phase compensation includes:

a phase compensator circuit for supplying a phase command to a RF power amplifier to compensate for an arbitrary phase shift; and

a phase detector for detecting the phase of the output power.

21. The system of either claim 19, wherein the RF power amplifier with phase compensation includes:

a phase compensator circuit for supplying a phase command to a RF power amplifier to compensate for an arbitrary phase shift; and

a phase detector for detecting the phase of the output power.

24. A method for delivering synchronous power, comprising:

delivering power and phase to a first load; and

delivering power and phase substantially equal to the power and phase delivered to the first load to a second load.

25. The method of claim 24, further comprising:

compensating for an arbitrary phase shift in the phase of the output to the first load; and

substantially maintaining the phase of the output to the first load.

26. The method of claim 24, further comprising:

compensating for an arbitrary phase shift in the phase of the output to the second load; and

substantially maintaining the phase of the output to the second load.

27. The method of claim 24, further comprising delivering power with an amplitude and phase equal to the amplitude and phase of the first load to one or more loads.

28. A digital and analog hybrid system for delivering power to a load, comprising:

means for providing a gain-bandwidth and a phase margin for substantially maintaining stability of output power; and

means for compensating for nonlinearities at the load.

29. A system for delivering synchronous power, comprising:

means for delivering power to a first dynamic load; and

means delivering power having a phase equal to phase of the first dynamic load to a second dynamic load.

30. A method for delivering power to a dynamic plasma load, comprising:

determining a switch of reactant gases that generate a plasma;

calculating a change in output power required to sustain a plasma load with the switched reactant gases;

supplying power equal to a power required to sustain the plasma load with the switched reactant gases; and

supplying power to the plasma load faster than the reactant gases change in the plasma.