System, method and apparatus for using optical data to monitor RF generator operations

摘要

A system and method monitoring a plasma with an optical sensor to determine the operations of a pulsed RF signal for plasma processing including a plasma chamber with an optical sensor directed toward a plasma region. An RF generator coupled to the plasma chamber through a match circuit. An RF timing system coupled to the RF generator. A system controller is coupled to the plasma chamber, the RF generator, the optical sensor, the RF timing system and the match circuit. The system controller includes a central processing unit, a memory system, a set of RF generator settings and an optical pulsed plasma analyzer coupled to the optical sensor and being capable to determine a timing of a change in state of an optical emission received in the optical sensor and/or a set of amplitude statistics corresponding to an amplitude of the optical emission received in the optical sensor.

主权项

1. A plasma processing system comprising:
a plasma chamber having a plasma region associated with an optical sensor that is directed toward the plasma region, wherein the optical sensor is configured to capture an optical emission from the plasma region, and the optical sensor produces an output sensor signal for the optical emission; at least one RF generator coupled to the plasma chamber through a match circuit; an RF timing system coupled to the at least one RF generator, wherein the RF timing system is configured to generate a timing reference signal; and a system controller coupled to the optical sensor, wherein the system controller is configured to process an optical pulsed plasma analyzer, wherein the optical pulsed plasma analyzer is configured to receive the output sensor signal from the optical sensor and is further configured to determine a set of amplitude statistics corresponding to an amplitude of the optical emission captured by the optical sensor, wherein to determine the set of amplitude statistics, the optical pulsed plasma analyzer is configured to,
subdivide a state of the timing reference signal into a plurality of time intervals; andidentify an amplitude statistic of the output sensor signal for each of the time intervals to control a setting of the at least one RF generator.