GROWTH AND DOPING PROPERTIES OF ALGAAS GAAS/INGAAS STRUCTURES ON NONPLANAR SUBSTRATES FOR APPLICATIONS TO LOW-THRESHOLD LASERS/

The growth behavior of AlGaAs/GaAs/InGaAs structures on non-planar (10 0) GaAs substrates has been studied. The structures were grown by atmo spheric pressure metalorganic chemical vapor deposition (MOCVD) on sub strates which have mesa stipes aligned along the (($) over bar 110) di rection with (100) mesa tops and (111)A sidewalls. The growth rates an d the doping of the AlGaAs/GaAs/InGaAs layers are shown to have a stro ng dependence on the crystallographic orientation as the sidewall appr oaches the (111)A plane. Growth temperature and III-V ratio also affec t the relative growth rate and the doping of the layers. Using the abo ve properties, we have grown and fabricated low threshold InGaAs/GaAs QW lasers by a single step MOCVD growth. Threshold current as low as 0 .5 mA for uncoated DQW lasers has been achieved.