Role of thin multiquantum wells in controlling intrinsic interface quality in molecular beam epitaxially grown heterostructures

A model based on Monte Carlo simulations and theory of statistical fluctuations is presented for molecular beam epitaxy growth of III-V semiconductors. It is shown that under normally employed growth conditions, cation surface migration controls the surface (interface) quality. The surface of a growing film gets rougher with increasing thickness of the film due to statistical fluctuations in the cation flux and limited cation migration. An important outcome of this theory is that the substrate temperature for high quality semiconductor surfaces and interfaces can be substantially reduced if growth is punctuated by thin layers (5–10 monolayers) of a low melting temperature semiconductor. Potential use of thin layers of InAs and GaAs for low-temperature growth of GaAs and AlGaAs, respectively, is discussed.