Control of Film Uniformity Properties in a Planetary Radial-flow Gallium Nitride Cvd System

The development and application of a geometrically-based uniformity criterion is presented for film uniformity optimization in a radial-flow GaN epitaxy reactor system. In this multi-wafer reactor system, individual wafers rotate on a rotating susceptor in a planetary motion to reduce the effects of reactant depletion on deposition uniformity; the uniformity criterion developed for this system gives an unambiguous criterion for minimizing non-uniformity of any film property, can be implemented in a run-to-run uniformity control scheme, and gives physical insight into the reactor operating conditions that most influence uniformity. Copyright 2005 IFAC.