Phase and frequency control of a radio frequency generator from an external source

• US 7,602,127 B2
• Filed: 04/18/2005
• Issued: 10/13/2009
• Est. Priority Date: 04/18/2005
• Status: Active Grant

• Current Assignee: MKS Instruments Incorporated
• Original Assignee: MKS Instruments Incorporated
• Inventors: Coumou, David J.
• Primary Examiner(s): Vu; David Hung
• Assistant Examiner(s): Le; Tung X
• Application Number:
  US11/108,626
• Publication Number:
  US 20060232471A1
• Time in Patent Office: 1,639 Days
• Field of Search: 315/111.21, 315/326, 315/111.41, 315/261, 324/464, 324/520, 219/121.43, 219/121.54, 118/723.I, 118/723.R
• US Class Current: 315/111.21
• 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 37/32174 Circuits specially adapted for controlling the RF discharge
• CPC Class Codes: H05B 31/26 Influencing the shape of arc discharge by gas blowing devices
• CPC Class Codes: H05H 1/46 using applied electromagnetic fields, e.g. high frequency or microwave energy H05H1/26 takes precedence

Abstract

Controlling a phase and/or a frequency of a RF generator. The RF generator includes a power source, a sensor, and a sensor signal processing unit. The sensor signal processing unit is coupled to the power source and to the sensor. The sensor signal processing unit controls the phase and/or the frequency of a RF generator.

Claims

1. A radio frequency (RF) system comprising:

a first agile frequency RF generator including;

a power source;

a sensor coupled to the power source; and

a sensor signal processing unit coupled to the power source and to the sensor, the sensor signal processing unit adapted to receive an input from an external source and to generate a first control signal controlling at least one of a first phase and a first frequency of a RF power signal from the first RF generator; and

a second agile frequency RF generator operable to receive a second control signal from the first RF generator, the second control signal controls at least one of a second phase and a second frequency of the second RF generator.

2. The RF generator of claim 1, wherein a variable frequency offset between the first and the second RF generators is controlled by the second control signal, and wherein the first and second control signals are RF signals.

3. The RF generator of claim 1, wherein the input is a user defined input.

4. A RF system comprising:

a first RF generator; and

a second RF generator coupled to the first RF generator, the first and the second RF generators each including;

a power source;

a sensor coupled to the power source;

a sensor signal processing unit coupled to the power source and to the sensor,

wherein the sensor signal processing unit for the first RF generator controls a phase and a frequency of the first RF generator and the sensor signal processing unit for the second RF generator control a phase and a frequency of the second RF generator.

5. The RF system of claim 4, wherein each sensor signal processing unit controls a variable phase offset for a fixed frequency.

6. The RF system of claim 4, wherein each sensor signal processing unit controls a variable phase offset for an agile frequency.

7. The RF system of claim 5, wherein a variable frequency between the first and the second RF generators is maintained through a control signal from the first RF generator to the second RF generator.

8. A method comprising:

coupling a sensor to a power source;

coupling a sensor signal processing unit to the power source and to the sensor;

receiving an input from an external source;

generating a control signal to control phase and frequency of a RF generator;

taking a derivative of a phase and frequency signal;

calculating frequency of a signal based on the derivative;

summing a frequency offset with the derivative;

updating a frequency error at a controller; and

sending a mixed frequency error to a digital frequency synthesizer from the controller.

9. The method of claim 8, wherein the input is one of a phase set point and a mix frequency set point.

10. The method of claim 8, wherein the external source is a user defined input.

11. The method of claim 8 further comprising:

receiving a phase offset from an external source;

generating a variable phase setpoint; and

controlling the phase of the RF generator.