The optimum time required for a chamber cleaning process is a complex function of different variables including thickness of the wall deposits, temperature of the chamber surfaces, etch rate of the deposits at the temperature and pressure of the cleaning process, and the chemical composition of the material that is being removed.
Ensuring that the cleaning process time matches only what’s needed to remove all the material on the chamber surfaces is important. If the processing time leaves the chamber under cleaned, material remains on the chamber surfaces that can accumulate and eventually produce particle contamination. If the processing time produces overcleaning, the chamber surfaces can be etched producing metal fluoride particles that can contaminate subsequent Chemical Vapor Deposition (CVD) processes. Over-cleaning also wastes expensive reagent gases and etching of some components in the chamber, such as pressure and temperature sensors, mechanical wafer handling components, etc., will shorten their lifespan leading to an increased operational cost of the CVD tool.
Explore how to accurately determine the endpoint of chamber clean to eliminate under and overcleaning of chamber surfaces for improved product yield and chamber lifetime.
