Radical output monitor for a remote plasma source and method of use

A plasma source for a processing system, comprising:

• at least one gas source configured to provide at least one gas;
• a plasma source body defining at least one gas inlet in fluid communication with the at least one gas source and at least one gas outlet, the plasma source having at least one passage having at least one passage surface formed within the plasma source body, the at least one passage in fluid communication with the at least one gas inlet and the at least one gas outlet;
• at least one power source surrounding at least a portion of the plasma source body, the at least one power source in communication with at least one power supply, the at least one power source configured to generate at least one plasma region within the plasma source body, the at least one plasma region configured to disassociate the at least one gas flowing within the passage forming at least one disassociated gas, the at least one disassociated gas evacuated from plasma source body via the at least one outlet;
• a first thermal sensor receiver formed within the plasma source body proximate to the at least one passage surface of the at least one passage;
• a first thermal sensor positioned within the first thermal sensor receiver, the first thermal sensor configured to measure a first temperature of at least one passage surface of the at least one passage at a first location;
• a second thermal sensor receiver formed within the plasma source body proximate to the at least one passage surface of the at least one passage, the second thermal sensor receiver formed within the plasma source body proximate to the at least one gas outlet;
• a second thermal sensor positioned within the second thermal sensor receiver, the second thermal sensor configured to measure a second temperature of the at least one passage surface of the at least one passage at a second location;
• and
• at least one thermal regulating device coupled to the plasma source body.

A method of monitoring the radical output from a plasma source, comprising:

• providing a plasma source body defining at least one gas inlet in fluid communication with at least one gas source and at least one gas outlet, the plasma source having at least one passage defined by at least one passage surface formed within the plasma source body, the at least one passage in fluid communication with the at least one gas inlet and the at least one gas outlet;
• flowing at least one input gas from the at least one gas source into the at least one passage via the at least one inlet;
• forming at least one plasma region within the plasma source body with at least one power source;
• disassociating at least a portion of the at least one input gas flowing thought the at least one passage to form at least one disassociated gas;
• measuring a first temperature resulting from recombination of the at least one disassociated gas with at least a first sensor positioned proximate to the at least one plasma region;
• and
• measuring at least a second temperature of at least one re-disassociated gas with at least a second sensor positioned distally from the at least one plasma region;
• and
• monitoring the radical output of the plasma source by comparing the first temperature of the recombination of the disassociated gas measure by the at least one first sensor to the second temperature of the at least one re-disassociated gas measured with the at least one second sensor.