Particle monitoring method for plasma reactors with moving gas distribution housings

摘要

Plasma reactors are used extensively in the manufacture of integrated circuits for the deposition and etching of thin films at low temperatures. Their range of operating temperatures and gas pressures make them highly susceptible to build-up of deposits on the inner surfaces of the reaction chamber which subsequently become dislodged by vibrations, stresses, and other aggravations and are dispersed within the system as particulates. The monitoring of particulate accumulation on wafers is conventionally done by subjecting a test wafer to a simulated operation within the tool under gas flow alone. Some types of plasma reactors incorporate oscillating gas dispersion housings in order to improve homogeneity of the gas mixture. The motion of these housings can induce significant particle displacement within the chamber. The correct monitoring procedure for these tools must therefore include the motion of the distribution housing in addition to the conventional procedures.