RF Pulse Edge Shaping

• US 20140118031A1
• Filed: 10/30/2012
• Published: 05/01/2014
• Est. Priority Date: 10/30/2012
• Status: Active Grant

• Current Assignee: MKS Instruments Incorporated
• Original Assignee: MKS Instruments Incorporated
• Inventors: RUGHOONUNDON, Amish, FISK, Larry J. II, RADOMSKI, Aaron T.
• Granted Patent: US 8,736,377 B2
• Time in Patent Office: Days
• US Class Current: 327/100
• 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 37/32146 Amplitude modulation, includes pulsing
• CPC Class Codes: H01J 37/32174 Circuits specially adapted for controlling the RF discharge
• CPC Class Codes: H03K 4/026 using digital techniques
• CPC Class Codes: H03K 5/00006 Changing the frequency modulating pulses H03K7/00; frequency dividers H03K21/00 - H03K29/00; additive or subtractive mixing of two pulse rates into one G06F7/605; pulse rate dividers G06F7/68

Abstract

A radio frequency (RF) generation module includes a power control module that receives first and second desired amplitudes of an output of the RF generation module in first and second respective states, and that outputs, based on the first and second desired amplitudes, input power setpoints corresponding to a transition from the first state to the second state. A frequency control module receives the input power setpoints and outputs frequency setpoints corresponding to the input power setpoints. A pulse shaping module receives the input power setpoints, the frequency setpoints, and an indication of when to transition from the first state to the second state, and transitions the output of the RF generation module from the first state to the second state based on the input power setpoints, the frequency setpoints, and the indication.

Claims

1. A radio frequency (RF) generation module, comprising:

a power control module that receives first and second desired amplitudes of an output of the RF generation module in first and second respective states, and that outputs, based on the first and second desired amplitudes, input power setpoints corresponding to a transition from the first state to the second state;

a frequency control module that receives the input power setpoints and outputs frequency setpoints corresponding to the input power setpoints; and

a pulse shaping module that receives the input power setpoints, the frequency setpoints, and an indication of when to transition from the first state to the second state, and that transitions an output signal from the first state to the second state based on the input power setpoints, the frequency setpoints, and the indication.

2. The RF generation module of claim 1, wherein:

the input power setpoints include a first power setpoint corresponding to the first state, a second power setpoint corresponding to the second state, and at least one of a step size, a number of steps, a step time, and a ramp time for transitioning between the first power setpoint and the second power setpoint; and

the frequency setpoints include a first frequency setpoint corresponding to the first state, a second frequency setpoint corresponding to the second state, and at least one of a step size, a number of steps, a step time, and a ramp time for transitioning between the first frequency setpoint and the second frequency setpoint.

3. The RF generation module of claim 1, wherein the input power setpoints are at least one of i) predetermined and stored in the RF generation module and ii) received as inputs from a user interface.

4. The RF generation module of claim 1, further comprising:

a pulse state control module that outputs the first and second desired amplitudes and the indication based on at least one of a desired pulse frequency and a desired duty cycle.

5. The RF generation module of claim 4, wherein:

the pulse state control module further outputs a desired pulse shape to at least one of the power control module and the pulse shaping module.

6. The RF generation module of claim 1, wherein at least one of the input power setpoints and the frequency setpoints are further based on a desired pulse shape of the output of the RF generation module.

7. The RF generation module of claim 6, wherein the desired pulse shape includes at least one of exponential pulse edges, linear pulse edges, and rounded pulse edges.

8. The RF generation module of claim 6, wherein the desired pulse shape does not change a desired pulse width of the output of the RF generation module.

9. The RF generation module of claim 1, wherein the pulse shaping module further comprises:

a frequency state control module that outputs a frequency control signal based on the frequency setpoints;

a power state control module that outputs a power control signal based on the input power setpoints; and

an output module that outputs the output of the RF generation module having pulses shaped according to the frequency control signal and the power control signal.

10. A method for operating a radio frequency (RF) generation module, the method comprising:

receiving first and second desired amplitudes of an output of the RF generation module in first and second respective states;

outputting, based on the first and second desired amplitudes, input power setpoints corresponding to a transition from the first state to the second state;

outputting frequency setpoints corresponding to the input power setpoints;

receiving the input power setpoints, the frequency setpoints, and an indication of when to transition from the first state to the second state; and

transitioning the output of the RF generation module from the first state to the second state based on the input power setpoints, the frequency setpoints, and the indication.

11. The method of claim 10, wherein:

the input power setpoints include a first power setpoint corresponding to the first state, a second power setpoint corresponding to the second state, and at least one of a step size, a number of steps, a step time, and a ramp time for transitioning between the first power setpoint and the second power setpoint; and

the frequency setpoints include a first frequency setpoint corresponding to the first state, a second frequency setpoint corresponding to the second state, and at least one of a step size, a number of steps, a step time, and a ramp time for transitioning between the first frequency setpoint and the second frequency setpoint.

12. The method of claim 10, wherein the input power setpoints are at least one of i) predetermined and stored in the RF generation module and ii) received as inputs from a user interface.

13. The method of claim 10, further comprising:

outputting the first and second desired amplitudes and the indication based on at least one of a desired pulse frequency and a desired duty cycle.

14. The method of claim 13, further comprising:

outputting a desired pulse shape.

15. The method of claim 10, wherein at least one of the input power setpoints and the frequency setpoints are further based on a desired pulse shape of the output of the RF generation module.

16. The method of claim 15, wherein the desired pulse shape includes at least one of exponential pulse edges, linear pulse edges, and rounded pulse edges.

17. The method of claim 15, wherein the desired pulse shape does not change a desired pulse width of the output of the RF generation module.

18. The method of claim 10, further comprising:

outputting a frequency control signal based on the frequency setpoints;

outputting a power control signal based on the input power setpoints; and

outputting the output of the RF generation module having pulses shaped according to the frequency control signal and the power control signal.