A low pressure open tube system with diethylzinc (DEZn) and phosphine (PH3) as precursors was used to study the Zn-diffusion in InP. This system offers a flexible and precise control of the diffusion parameters. We investigated the effect of the DEZn and PH3 partial pressures and of the diffusion temperature and time on the hole and Zn concentration profiles. Annealing the samples leads to an increased hole concentration due to out-diffusion of interstitial Zn donors. The Zn and hole concentration profiles were obtained by secondary-ion mass spectroscopy and C–V etch profiling showing maximum hole concentrations between 1017 cm−3 and 4×1018 cm−3 for diffusion depths from 0.3 to 2 μm.

No abstract

No abstract

We have investigated the activation by post-deposition annealing of Zn and Cd acceptors incorporated in InP during epitaxial growth using metalorganic vapor phase epitaxy. Growth was carried out at 20 mbar and atmospheric pressure for Zn- and Cd-doped samples, respectively, using TMI, PH3, DEZn, and DMCd as sources. Post-epitaxial annealing in a N2 atmosphere at temperatures in the range of 370–470 °C leads to complete activation of the acceptors. This process is strongly temperature dependent and a distinct effect of a GaInAs overlayer was observed. The activation energy is the same for Zn- and Cd-doped samples. It is suggested that the diffusion of vacancies plays a determining role in activating the dopant.