Molecular beam epitaxy arrangement

Fig. 8. Energy below the conduction band of levels reported in the literature for GaAs. Arrangement and notations are the same as for Figs. 4 and 5. Notations not defined there are epitaxial layer on semi-insulating substrate (EPI/SI), boat-grown (BG), vapor phase epitaxial layer on semi-insulating substrate (VPE/SI), melt-grown (M), molecular beam epitaxy (MBE), horizontal Bridgman (HB), irradiated with 1-MeV electrons or rays (1-MeV e, y), thermally stimulated capacitance (TSCAP), photoluminescence excitation (PLE), and deep level optical spectroscopy (DLOS).

Molecular beam epitaxy. Epitaxial techniques are techniques of arranging atoms in single-crystal fashion on crystalline substrates so that the lattice of the newly grown film duplicates that of the substrate. If the film is of the same material as the substrate, the process is called homoepitaxy, epitaxy, or simply epi. The most important applications here are Si epi on Si substrates and GaAs epi on GaAs substrates. If the deposit is made on a substrate that is chemically different, the process is termed heteroepitaxy. An important application is the deposition of silicon on an insulator (SOI) e.g. with sapphire (AI2O3) as the insulator in the silicon on sapphire (SOS) process. 

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