We investigated the metal organic vapor pressure epitaxy growth of AlxGa1-xAsySb1-y on InAs substrates using the precursors tritertiarybutylaluminum (TTBAl), triethylgallium (TEGa), tertiarybutylarsine (TBAs) and triethylantimony (TESb). Optimization of the substrate stabilization, the annealing time and the purging time between stabilization and growth was necessary to achieve reproducible solid composition, high structural quality and mirror-like surface morphology. To avoid phase separation in the material, substrate temperatures higher than approximately 610 degreesC were required. The best electrical properties were achieved for V/III-ratios between 1.8 and 4 with growth temperatures between 625 degreesC and 645 degreesC. With increasing x(A1) from 0.20 to approximately 0.48, the p-type background doping level increased from 4x10(17)cm(-3) up to 2x10(18)cm(-3) whereas the corresponding mobilities decreased from 150 to 50cm(2)/V s. SIMS measurements indicate that the increased hole concentration is due to carbon incorporation. Using new "EpiPure" TEGa and TESb batches supplied by Epichem Ltd.. which were synthesized using a completely oxygen-free route, the electrical and optical properties of AlGaAsSb were improved.