Optical sensors for measuring properties of consumable parts in a semiconductor plasma processing chamber

A semiconductor processing system includes a processing chamber configured to perform a semiconductor manufacturing process on each of a plurality of wafers. The processing chamber includes at least one consumable component, and a substrate handling module located proximate the processing chamber and in communication with the processing chamber via a wafer access port. The wafer handling module includes a wafer handling robot configured to transfer each of the wafers between to the substrate handling module and the processing chamber through the wafer access port, and an optical diagnostic system including an optical sensor configured to detect an optical signal from the at least one consumable component. A controller is configured to cause the processing chamber to perform the semiconductor manufacturing process on each respective wafer and to cause the optical diagnostic system to detect the optical signal during a time when the processing chamber is not performing the semiconductor manufacturing process on