Preparation of GaAs and Ga1-xAlxAs Multi-Layer Structures by Metalorganic Molecular Beam Epitaxy

Abstract

Metalorganic molecular beam epitaxial (MOMBE) growth of GaAs and (GaAl)As using triethylgallium (TEG) and triethylaluminum (TEA) has been studied. N-GaAs/p-GaAs multi-layer structures were prepared by applying an alternating ionization voltage to hydrogen. Single-crystal Ga_1-x Al _x As ternary alloy with good surface mophology was successfully grown by introducing TEA as an Al source. The epitaxial layers typically showed p-type conduction with a carrier concentration of more than 10¹⁸ cm^-3, this being due to residual carbon. A (GaAl)As/GaAs multiquantum well (MQW) heterostructure was fabricated by switching TEA and it was observed that the photoluminescence peak energies from the MQW structures were shifted to the higher energy position. Furthermore, selective growth of GaAs and (GaAl)As on a partly SiO₂ masked GaAs substrate was investigated. In the MOMBE growth of (GaAl)As, polycrystalline film was deposited on the SiO₂ masked region, while no deposition took place in the growth of GaAs.