The design and operation of a second generation silicon MBE apparatus are described. A large sample loading interlock permits rapid introduction of standard format 3–4-in.-diam silicon and sapphire substrates. Silicon and metallic species are deposited from dual e-beam evaporation sources at rates of up to 1/3 μm/min. Dopants are introduced by evaporation from conventional Knudsen cells or by simultaneous, low energy ion implantation. Silicon, metal and ionized dopant fluxes are directly sensed and regulated to within ∠1% of preprogrammed values. Rotation of the substrate yields deposition uniformity of ?1% across a 3-in. wafer. The system includes instrumentation for low and high energy electron diffraction, Auger electron spectroscopy and residual gas analysis.