Detecting an excursion of a cmp component using time-based sequence of images

A computer program product, tangibly embodied in computer-readable media, comprising instructions to cause one or more computers to:

• store a time-based sequence of reference images of a component of a polishing system performing operations during a test operation of the polishing system;
• receive from a camera a time-based sequence of monitoring images of an equivalent component of an equivalent polishing system performing operations during polishing of a substrate;
• determine a difference value for the time-based sequence of monitoring images by comparing the time-based sequence of reference images to the time-based sequence of monitoring image using an image processing algorithm;
• determine whether the difference value exceeds a threshold;
• and
• in response to determining the difference value exceeds the threshold, indicate an excursion.

A method for monitoring operations of a polishing system, the method comprising:

• obtaining a time-based sequence of reference images of a component of the polishing system performing operations during a test operation of the polishing system;
• receiving from a camera a time-based sequence of monitoring images of an equivalent component of an equivalent polishing system performing operations during polishing of a substrate;
• determining a difference value for the time-based sequence of monitoring images by comparing the time-based sequence of reference images to the time-based sequence of monitoring image using an image processing algorithm;
• determining whether the difference value exceeds a threshold;
• and
• in response to determining the difference value exceeds the threshold, indicating an excursion.