Abstract
Integrated optics and integrated microwave circuits require extremely uniform epitaxial layer thicknesses, composition profiles, and doping profiles. With a sample rotating mechanism, molecular beam epitaxy can for the first time prepare GaAs and Al x Ga 1-x As layers with thickness variation of less than 1% over a lateral dimension of 5 cm. The variation of AlAs mole fraction of the Al 0 . 3 Ga 0 . 7 As over a 10-cm 2 area was less than 0.4%. The variation of the "pinch-off" voltage for a field effect transistor structure was less than 1.4% over a 10-cm 2 wafer. These results represent the most uniform epitaxial layers ever prepared with any crystal growth technology.