Infrared spectroscopic evidence of silicon related hydrogen complexes in hydrogenated <i>n</i>-type GaAs doped with silicon

Abstract

Infrared absorption spectroscopy has been performed on hydrogenated and deuterated n-type silicon-doped GaAs. It reveals the presence of a sharp vibrational mode at 890 cm−1 in hydrogenated samples and at 637 cm−1 in deuterated ones. These bands are absent in undoped GaAs. Analysis of the isotopic shift frequency reveals that the band is associated with a hydrogen–arsenic bond where arsenic is supposed to sit as a first nearest neighbor of the silicon donor atom giving rise to (SiAs3)As-H complexes. Isochronal annealing experiments show the direct correlation between the absorption line intensity and the amount of neutralized donors, confirming the view that the extra electrons of the silicon donors are involved in the hydrogen–arsenic bonds.