Growth and characterization of GaAs layers on Si substrates by migration-enhanced molecular beam epitaxy

Abstract

We first report on migration-enhanced molecular beam epitaxial (MEMBE) growth and characterization of the GaAs layer on Si substrates (GaAs/Si). Excellent surface morphology GaAs layers were successfully grown on (100)Si substrates misoriented 4° toward the [110] direction. The MEMBE growth method is described, and material properties are compared with those of normal two-step MBE-grown or in situ annealed layers. Micrographs of cross-section view transmission electron microscopy (TEM) and scanning surface electron microscopy (SEM) of MEMBE-grown GaAs/Si showed dislocation densities of 1×107 cm−2, over ten times lower than those of normal two-step MBE-grown or in situ annealed layers. AlGaAs/GaAs double heterostructures have been successfully grown on MEMBE GaAs/Si by both metalorganic chemical vapor deposition and liquid phase epitaxy.

Methods to Decrease Defect Density in GaAs/Si Heteroepitaxy

“…Another very promising method is migration-enhanced epitaxy in which the Ga and As flux is alternating [34] or modulation enhanced epitaxy with continous As flux and intermittend Ga flux [35]. It was demonstrated that this kind of growth ensures two dimensional growth and results in very narrow PL lines.…”