PHOTOLUMINESCENCE OF STRAINED SI1-YCY ALLOYS GROWN AT LOW-TEMPERATURE

The photoluminescence of strained Si1-xCx alloys grown at low temperature by rapid thermal chemical vapor deposition is investigated. The photoluminescence spectra are mainly characterized by a deep level broadband at low energy which subsists up to room temperature. This low energy emission is associated with the low-temperature growth process required for the incorporation of carbon into substitutional sites. The stability of the layers after thermal annealing is monitored using this low energy radiative recombination. A blue shift of the photoluminescence energy peak is observed and the peak intensity presents a maximum versus annealing time. The blue shift and the associated increased linewidth is explained in terms of the local strain induced band-gap fluctuations. Infrared transmission spectra of the annealed samples suggest that silicon carbide precipitates appear during the anneal and that oxygen and carbon complexes contribute to the formation of the deep level band.© 1995 American Institute of Physics.