Multirate processing for metrology of plasma RF source
AssigneeENI Technology, Inc.
InventorsDavid J. Coumou, Michael L. Kirk
Life of this patent
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Abstract
An RF generator is provided for use in an RF plasma system. The RF generator includes: a power source that is operable to generate RF power signals at a tuned frequency; a sensor unit that is adapted to detect the RF power signals and operable to generate analog signals representative of the RF power signals, where the analog signals include a frequency of interest and a plurality of interfering frequency components; and a sensor signal processing unit that is adapted to receive the analog signals from the sensor unit and to band limit the analog signals within a predefined bandwidth that passes the frequency of interest and rejects interfering frequency components.
Claims22
An RF generator residing in an RF plasma system, comprising:
- a power source operable to generate RF power signals at a tuned frequency within a tunable frequency range;
- a sensor unit adapted to detect the RF power signals and operable to generate analog signals indicative of the RF power signals, the analog signals having a frequency component of interest related to the tuned frequency of the power source;
- and
- a sensor signal processing unit adapted to receive the analog signals from the sensor unit and to band limit the analog signals within a predefined bandwidth, wherein the predefined bandwidth of the signal processing unit is adjustable to pass the frequency component of interest and reject interfering frequency components.
An RF plasma system, comprising:
- a plasma chamber;
- an RF generator that deliver RF power, signals to the plasma chamber;
- and
- a matching network interposed between the RF generator and the plasma chamber to match impedances between the RF generator and the plasma chamber, wherein the RF generator further includes
- a tunable power source operable to generate RF power signals at a tuned frequency within a tunable frequency range;
- a sensor unit adapted to detect the RF power signals and operable to generate analog signals indicative of the RF power signals, the analog signals having a fundamental frequency component and a plurality of interfering frequency components;
- and
- a sensor signal processing unit adapted to receive the analog signals from the sensor unit and to band limit the analog signals within a predefined bandwidth, wherein the predefined bandwidth of the signal processing unit is adjustable to pass the fundamental frequency component and reject interfering frequency components.
An RF generator residing in an RF plasma system, comprising:
- a first power source operable to generate RF power signals at a first fixed frequency;
- a second power source operable to generate RF power signals at a second fixed frequency;
- a sensor unit adapted to detect the RF power signals generated by one of the first and second power sources and operable to generate analog signals indicative of the RF power signals, the analog signals having a frequency of interest related to the fixed frequency of the power source and a plurality of interfering frequency components;
- and
- a sensor signal processing unit being implemented in a digital domain, the sensor signal processing unit adapted to receive the analog signals from the sensor unit and to band limit the analog signals within a predefined bandwidth that passes the frequency of interest and rejects interfering frequency components.
A method for generating digital control signals that track radio frequency (RF) power signals generated by an RF generator, comprising:
- generating analog signals indicative of the RF power signals generated by the RF generator, the analog signals having a frequency of interest that is related to a tuned frequency of the RF generator;
- converting the analog signals into digital power signals;
- generating digital mixing signals in accordance with a frequency setpoint;
- combining the digital mixing signals with the digital power signals to form digital complex coordinates signals;
- reducing a data rate associated with the digital complex coordinate signals;
- and
- shaping frequency response of the digital complex coordinate signals, thereby deriving digital control signals that track RF power signals generated by an RF generator.
Dependencies are inferred from the claim text.