Diffusion of zinc acceptors in InAsP by a metal-organic vapor-phase diffusion technique, whereby a low-pressure metal-organic vapor-phase epitaxy with dimethylzinc and phosphine is utilized as an open tube diffusion system, is demonstrated to accurately control the diffusion depth in the submicrometer range. The annealing effect on the zinc diffusion profiles in InAsP was found to be the activation of zinc acceptors similar to that in InP, but the maximum hole concentration of1×1019 cm−3for the zinc diffusion in InAsP was achieved. ©1997 American Institute of Physics.