SELECTIVE-AREA METALORGANIC CHEMICAL-VAPOR-DEPOSITION GROWTH FOR HEXAGONAL-FACET LASERS

In order to obtain low threshold hexagonal-facet (HF) lasers by reducing their size! it is necessary to know the selective growth conditions of a hexagonal prism on a smaller area. We describe the metalorganic chemical vapor deposition (MOCVD) growth conditions for GaAs and AlGaAs hexagonal prisms on a SiO2 masked (111)B substrate. The crystal shape and the facet strongly depend on the size of the mask windows, on the working pressure during growth, and on the growth parameters of the substrate temperature and the partial pressure of arsine. Furthermore, we explain the mechanism of the hexagonal prism growth by using the change of growth rate between low-index facet planes. By using optimized growth conditions, a 2 mu m sized I-IF laser structure with flat GaAs/AlGaAs heterointerface can be grown.