System and method for detecting excursion in plasma processing

An excursion detection and control system for detecting excursion in a downstream plasma processing and controlling downstream plasma processing, the excursion detection and control system comprising:

• an electrode assembly inserted in an exhaust line of a plasma processing chamber to receive its effluent as a feed gas;
• a power generator to generate an energy for ionizing the received feed gas in the electrode assembly, wherein the ionization of the feed gas leads to a formation of a plasma environment to create a small capacitively coupled plasma;
• a dual directional coupler coupled between the electrode assembly and the power generator to track one or more harmonics that are produced due to non-linearity of an impedance in the plasma environment, wherein the one or more harmonics are associated with at least one of:
• voltage and current;
• one or more spectrum analyzers to:
• create a fingerprint of energy distribution in frequency space based on the tracked one or more harmonics;
• compare, in real-time, the created fingerprint with a reference spectra of an ideal plasma processing, stored in a historical database, to detect deviation of the fingerprint with the reference spectra;
• detect an excursion in the plasma processing based on the detected deviation of the fingerprint with the reference spectra;
• and
• a recommendation module to generate one or more recommendations to control the detected excursion, wherein the one or more recommendations are generated based at least on one of:
• the detected deviation and associated historical data related to corrective action stored in a corrective action database.

An method for detecting excursion in plasma processing and controlling plasma processing, the method comprising:

• tracking one or more harmonics that are produced due to nonlinearity of an impedance of a plasma environment, wherein the one or more harmonics are associated with at least one of:
• voltage and current;
• creating a fingerprint of energy distribution in frequency space based on the tracked one or more harmonics;
• comparing, in real-time, the created fingerprint with a reference spectra of an ideal plasma processing, stored in a historical database, to detect deviation of the fingerprint with the reference spectra;
• detecting an excursion in the plasma processing based on the detected deviation of the fingerprint with the reference spectra;
• and
• generating one or more recommendations to control the detected excursion, wherein the one or more recommendations are generated based at least on one of:
• the detected deviation and the associated historical data related to corrective action stored in a corrective action database.