The effect of three gettering procedures on the variation of the grain boundary defect density in multicrystalline silicon (mc-Si) was analyzed. The effective defect density (NB) was calculated using a theoretical model which considered the potential barrier induced by the grain boundary as being due to structural defects and impurities. The results were compared to those obtained from C-V measurements. The potential barrier was evaluated from the dark current-voltage (I-V) characteristic performed across the grain boundary. In addition to rapid thermal annealing, Al was used in the first gettering procedure. In the second one, porous silicon was used whereas, in the third one, chemical damage (grooving) was produced. The mc-Si wafers were annealed in an infra-red furnace, under the same conditions, at 600 to 1000C.

Gettering Effect in Grain Boundaries of Multi-Crystalline Silicon. H.Nouri, M.Bouaïcha, M.B.Rabha, B.Bessaïs: Physica Status Solidi C, 2012, 9[10-11], 1937-41