RELATIONSHIP BETWEEN POROUS SILICON FORMATION AND HYDROGEN INCORPORATION

Secondary ion mass spectroscopy was used to study the incorporation of deuterium into Si during the formation of porous silicon in fluoride D2O-based solutions. Results show that the deuterium diffuses from the pore tips towards the bulk silicon and remains in the pore walls in a high concentration. Measurements of the thickness of porous silicon s uggest that the penetration of H species is a necessary condition for the porous Si layer to form. A simple model illustrates how the initia tion of pores occurs by selective dissolution of H-induced structural defects. (C) 1997 Elsevier Science S.A.