Investigation on the materials of heavily Mg-doped AlInP layers for laser diode structure

High concentration p-type AlInP material is an important layer to achieve low resistant and large carrier confinement in short-wavelength red-light laser diodes (LDs). To investigate the Mg doping behavior and other characteristics in the red-light LDs with tensile GaInP well structure, two LDs wafers with different Mg-doped AlInP cladding layers were grown by the metalorganic chemical vapor deposition (MOCVD) method. Incorporation and activation behavior of Mg atoms in heavily-doped AlInP were analyzed by the comparisons between hole concentration and atom concentration. We demonstrate that it is possible to achieve hole concentration above 1018 cm−3 using Mg dopant in AlInP layers just by an in-situ annealing. Furthermore, a hole concentration as high as 2.92 × 1018 cm−3 was achieved after post rapid thermal annealing in the N2 atmosphere, which is the highest hole doping concentrations reported to-date for the p-AlInP material.