A custom‐designed MBE system has been used for device fabrication with high throughput. Up to six, 2 in. diameter substrates can be prepared and loaded into the system at once. The growth cycle for a FET structure is typically 2–3 hr. As many as 200 FET wafers with a total of more than 300 μm epitaxial layers can be grown between source replenishments. With continuous azimuthal rotation of the substrate, extreme uniformity in doping and thickness was achieved. The surfaces of the epitaxial layers were highly specular. The irregularly shaped defects commonly associated with the gallium spitting problem were eliminated. The remaining surface defects were oval‐shaped with a density < 104 cm−2. Silicon nitride was used to protect the back side of the substrate from indium attack during growth. Doping concentrations from to were obtained using Sn as dopant. Highest Hall mobilities measured were 7,600 cm2/Vsec at 300 K and 67,000 cm2/Vsec at 77 K. State‐of‐the‐art FET's were fabricated from materials grown by using this system.