Dopant-type effects on the diffusion of deuterium in GaAs

Abstract

The diffusion depth and total amount of deuterium incorporated in GaAs during plasma exposure is found to depend strongly on the conductivity type of the surface. A shallow $n^{+}$ layer inhibits the in-diffusion of deuterium, consistent with that species having a level in the upper half of the GaAs band gap. The deactivation of donors and acceptors by deuterium is then the result of different chemical reactions based on its different charge states in n- and p-type material. Zn acceptors display a reactivation energy of 1.6 eV, less than the typical value for donors of 2.1 eV.