Carbon doping of GaAs and AlGaAs layers grown by low-pressure metalorganic chemical vapor deposition, using triethylgallium. trimethylaluminum and arsine as growth precursors and carbon tetrachloride as dopant precursor, were investigated, Doping level dependence on growth temperature. growth rate, V/III ratio and AlAs mole fraction was established. InGaAs/AlGaAs DQW broad waveguide separate confinement laser heterostructures with different p-clad doping have been studied. Heterostructures design and optimization of active area growth conditions have been fulfilled to obtain high-power operation of laser diodes (LDs) with lock transverse divergence. Carbon tetrachloride and diethylzinc were used as p-type dopant precursors. There were investigated three types of heterostructures: (a) C-doped AlGaAs p-clad and heavy C-doped GaAs contact layer, (b) C-doped AlGaAs p-clad and heavy Zn-doped GaAs contact layer, (c) Zn-doped AlGaAs p-clad and heavy Zn-doped GaAs contact layer. Broad area LDS were manufactured and analyzed. As a result the optimal p-tvpe dopant precursor for high-power LDs as discussed. (C) 2002 Elsevier Science B.V. All rights reserved.