System and method for endpoint detection

A method of processing a substrate, the method comprising:

• processing a substrate by exposing the substrate in a processing chamber;
• removing an exhaust gas from the processing chamber to an exhaust gas line;
• generating an exhaust plasma in an exhaust chamber from the exhaust gas, the exhaust chamber connecting to the processing chamber through the exhaust gas line;
• detecting a hyperspectral image from the exhaust plasma using a hyperspectral imaging (HSI) camera;
• and
• performing an endpoint detection (EPD) of the processing of the substrate based on the hyperspectral image.

A method of endpoint detection (EPD) based on a hyperspectral image, the method comprising:

• performing a survey scan of a hyperspectral image across a full range of wavelengths during plasma processing a substrate to establish a baseline spectral database;
• selecting at least one wavelength of the hyperspectral image for a plasma processing based on optical emission properties of gases or byproducts during the plasma processing;
• and
• while performing a process having an end point in a processing chamber,
• collecting the hyperspectral image at the selected wavelength over time during the plasma processing;
• and
• detecting the end point of the process based on changes of the collected hyperspectral image.