Abstract: An apparatus and technique for measuring a concentration of radical particles within a gas sample obtained from a location within a semiconductor processing system having a process chamber while a process is being performed within the process chamber includes obtaining radical data corresponding to the measured concentration of radical particles, comparing the obtained radical data to at least one threshold and outputting a control signal when a result of the comparing indicates that the obtained radical data has a predetermined relationship with the at least one threshold. The first control signal can be configured to cause a chamber recovery process to be performed within the process chamber or indicate that a chamber recovery process should be performed within the process chamber.

Abstract: An apparatus for feedback control in plasma processing systems using radical sensing, and a method for feedback control in plasma processing systems using radical sensing, the apparatus comprising at least one process gas supply system configured to output at least one process gas, at least one plasma source configured to receive the at least one process gas and generate at least one radical flow, at least one process chamber in communication with the at least one plasma source, wherein the process chamber receives the at least one radical flow and directs at least a portion of the at least one radical flow to one or more devices, the process chamber configured to output at least one process chamber output, at least one gas analyzer in communication with and configured to sample at least one of the at least one process gas, at least one radical flow, at least one radical flow within the at least one process chamber, and the at least one process chamber output, and at least one controller in communication with