The growth chamber holds all effusion cells, a Stanford Research Systems RGA 200 mass spectrometer and Bayard-Alpert type pressure and flow sensors. A reflection high-energy electron diffraction (RHEED) system, consisting of a Staib electron gun and a fluorescent screen monitored by a CCD camera enable the analysis of surface reconstructions and real-time determination of deposition rates and material composition. During standby mode the pressure inside the growth chamber is around 10^-10 Torr.