Controlled enlargement of pores by annealing of porous silicon



In the present work, a possibility to use thermal annealing of porous silicon to enlarge the pore sizes has been studied. The size of the pores can be increased by controlling the annealing temperature and time. The pore enlargements from 10 nm even up to 100 nm can be obtained without destroying the pore structure. In all studied cases, annealing was found to decrease the surface areas and pore volumes of porous silicon, but the effects of annealing as a function of temperature were found to be strongly dependent on the initial porosity of samples. The crystallinity of the annealed samples was studied with XRD and the obtained results were used to explain differences observed in the pore sizes after the HF treatment of annealed samples. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)