Effects of arsenic source molecule on N-H related defects formation in GaAsN grown by chemical beam epitaxy

The formation mechanism of N-H related defects in GaAsN grown by chemical beam epitaxy is studied by the isotope effects on the local vibration modes (LVMs). When the deuterated tris(dimethylamino)arsenic (TDMAAs) is used as an arsenic source, new signals appear in the spectrum and they are attributed to the N-D related LVM signals. Therefore, the As source molecule contributes to the formation of N-H related defects in GaAsN. When TDMAAs flow rate increases, the concentration of N-H related defects at 2952cm^-1 increases. These results suggest that N-CH₃ in the molecule is one of the origins of the N-H at 2952cm^-1 in the grown films.