Hydrogen passivation and reactivation of shallow Zn acceptors in GaAs

We report on a study of the hydrogenation of melt-grown Zn-doped GaAs, using a remote DC plasma system. Depth profiles of the free carrier concentration revealed the extent of passivation of the hydrogenated GaAs. Annealing at temperatures between 90 and 160° C for various times, with a reverse bias applied to the Schottky diode, allowed us to observe the reactivation of the Zn-acceptors in the high-field space-charge region of the diode. The thermal dissociation of the electrically neutral ZnH complex is found to obey first-order kinetics, with a dissociation energy EZnH = 1.33 ± 0.03 eV. © 1991.