ANNEALING EFFECTS ON HYDROGEN PASSIVATION OF ZN ACCEPTERS IN ALGAINP WITH P-GAAS CAP LAYER GROWN BY METALORGANIC VAPOR-PHASE EPITAXY

We have investigated the hydrogen passivation mechanism of Zn accepters in a p-AlGaInP layer with a p-GaAs cap layer, grown by metalorganic vapor phase epitaxy (MOVPE), by observing post-epitaxial annealing effects on the activation of Zn accepters. The post-epitaxial annealing was carried out in ambiences containing hydrogen, arsine, and phosphine gas in the temperature range of 300-750 degrees C. The activation of Zn accepters depended strongly on the cooling conditions after the annealing and the p-GaAs cap layer thickness. These phenomena are associated with the atomic hydrogen which is released from the arsine by decomposition and diffuses into the p-AlGaInP layer to form the P-H bonds through the p-GaAs cap layer in the temperature range of 400-500 degrees C during cooling step after the post-epitaxial annealing.