Molecular Beam Epitaxy

Abstract

Molecular beam epitaxy (MBE) is an exciting field for research, development, and even production. With MBE one can easily grow layers of a few monolayers with atomically abrupt interfaces and with arbitrary composition or doping profile. This chapter concerns monitoring and control of growth rates and both group III and group V compositions by reflection high-energy electron diffraction (RHEED), reflection or desorption mass spectroscopy, and pyrometric interferometery. RHEED, mass spectroscopy, and pyrometric interferometry techniques are reviewed here, but other techniques including multiple wavelength pyrometry and ellipsometry are also being pursued. Tsang et al. first studied the growth behavior of CBE growth of GaAs by RHEED oscillations. A complication in growing ternary compounds is that due to the nature of chemical reactions on the surface the growth rate of the binary compounds in a ternary compound is affected by the presence of other molecular species on the surface, resulting in composition changes.