EBIC AND TEM ANALYSIS OF THE ELECTRICAL-ACTIVITY OF SIGMA = 25 AND SIGMA = 13 SILICON BICRYSTALS AFTER THERMAL TREATMENTS

The EBIC contrast diffusion lengths and recombination velocities for two coincidence grain boundaries are measured by the Donolato method after thermal treatments. The main origin of the contrast is attributed to copper-rich precipitates, Cu3Si, although oxygen, determined by infrared spectroscopy, may also have to be taken into account. The increase of the EBIC contrast with temperature and its nature, dotted or uniform, are controlled by the precipitate density at the grain boundary.