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 cm2, 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.