FACET EVOLUTION OF CCL4-DOPED AL0.5GA0.5AS/GAAS MULTILAYERS DURING METALORGANIC CHEMICAL-VAPOR-DEPOSITION ON PATTERNED GAAS SUBSTRATES

Abstract

We have investigated the facet evolution of Al0.5Ga0.5As/GaAs multilayers on mesa- or groove-patterned GaAs substrates during metalorganic chemical vapor deposition (MOCVD) as a function of growth temperature and CCl4 flow rate. Instead of the conventional evolution of a (433)A side wall facet for undoped Al0.5Ga0.5As/GaAs multilayers on a mesa, we have observed (511)A or (411)A facet evolutions during MOCVD growth in the presence of CCl4. In addition, the ratio of the growth rates of both GaAs and Al0.5Ga0.5As on the side wall facets and the (100) mesa top are remarkably enhanced compared to the growth without CCl4. Additionally fast planarization on a groove, which is desirable for device application, has been observed. The growth rate ratio shows strong dependencies on growth temperature and CCl4 flow rate indicating that the CCl4 supply rate can be an adequate parameter for lateral growth control. Using these characteristics, we have fabricated CCl4-doped quantum wires (QWRs) on V-groove structures. Extremely enhanced thickness of the QWR on a V-groove due to CCl4 effect is observed.