THERMAL-STABILITY OF DOPANT-HYDROGEN PAIRS IN GAAS

The thermal stability of dopant-hydrogen complexes in hydrogenated n- and p-type GaAs(1-2 X 10(17) cm-3) has been determined by examining their reactivation kinetics in reverse-biased Schottky diodes. The reactivation process is first-order for all of the dopants, with thermal dissociation energies (E(D)) of 1.45 +/- 0.10 eV for Si(As) acceptors, 1.25 +/- 0.05 eV for Si(Ga) donors, 1.20 +/- 0.10 eV for Sn(Ga) donors, 1.25 +/- 0.10 eV for Zn acceptors, 1.35 +/- 0.05 eV for C(As) acceptors, and 1.15 +/- 0.10 eV for Be acceptors. The dissociation frequencies (v) are thermally activated of the form nu(D) = nu-0E(-ED/kT), with the nu-0 values in the range 1-5 X 10(13) s-1. The results are consistent with much of the H being present as H+ in p-type material, and H- in n-type material.