Activation of Zn and Cd acceptors in InP grown by metalorganic vapor phase epitaxy

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.

Application of the point-defect analysis technique to zinc doping of MOCVD indium phosphide

“…They conclude that Zn impurity incorporation is controlled by the V/III ratio. The effect of post growth cooling ambient (H 2 only, PH 3 and H 2 , AsH 3 and H 2 ) on the electrical activation of Zn and Cd dopants in MOCVD InP has also been studied and the atomic hydrogen released from the pyrolysis of the hydrides has an influence on the doping level of p-InP which has been postulated to form neutral point defect complexes with donor-like Zn interstitials as well as hole-like Zn in the indium vacancies [25][26][27][28].…”