Structural changes induced by nitrogen in the a-Ge:H network

Abstract

The structural modifications induced by the incorporation of nitrogen (2 at.%<CN<6 at. %, CN=N concentration) in radio frequency-sputtered hydrogenated amorphous germanium (a-Ge:H) has been studied by infrared spectroscopy. At all N concentrations there is a substantial increase of the density of voids, as indicated by the strength of the absorption band associated with the surface-like stretching vibration of the Ge–H dipole. As CN increases, the peak position of this mode shifts to smaller values. These effects are also detected through the analysis of the wagging vibration modes of the Ge–H dipole. Comparison of the present results with similar data for H-free a:GeN indicates that the presence of H in the reaction hinders the incorporation of the NGe3 skeletal group, characteristic of β-Ge3N4. The overall data indicate that almost all N incorporates in N–H and N–H2 configurations, which are responsible for the formation of a large quantity of small-size voids.

Low temperature annealing of amorphous gallium arsenide films

“…The structural and electronic properties of amorphous semiconductors are sensitive to the method of preparation [13,16], deposition conditions [13,16], thermal annealing [5,6,16], chemical doping [13,17], among other factors. In an earlier study [18], we found that both optical and electric properties of a-GaAs films depend on crucible temperature and not on As composition (or Ga).…”

Dopagem tipo-n e mudanças estruturais induzidas pelo nitrogênio de filmes de germânio amorfo hidrogenado

“…Para verificar esta suposição, posteriormente foram crescidas por rf-sputtering duas séries de filmes de nitreto de germânio amorfo hidrogenado (a-Ge(N):H), numa faixa de 2 a t . % ~ CN ~ 6. at.%, uma usando N 2 e a outra, NH 3 (maiores detalhes sobre estes filmes encontram-se no Capítulo 4) 44 . Uma importante pergunta é se a densidade das configurações NH e NH2, inferida a partir das medidas IR, depende do tipo do gás precursor do N utilizado.…”