A study was made of simultaneous phosphorus and boron diffusion gettering of iron in silicon by physical modelling. Improvements were made to the previously used models for boron diffusion gettering and phosphorus diffusion gettering. It was shown that the improved model was suitable for analyzing the gettering efficiency in advanced solar cell structures with phosphorus doped (n+) and boron doped (p+) layers by comparing simulations with experimental results. The simulations indicated that during a low temperature step with high iron concentration, an additional p+ layer reduced the time needed for effective gettering, whereas under low supersaturation segregation to the n+ layer was the dominant gettering mechanism.

Analysis of Simultaneous Boron and Phosphorus Diffusion Gettering in Silicon. J.Schön, M.C.Schubert, W.Warta, H.Savin, A.Haarahiltunen: Physica Status Solidi A, 2010, 207[11], 2589–92