Study of porous silicon obtained by krypton ion implantation and laser annealing

An ellipsometric technique is used to study the formation of a finely porous layer saturated with atoms of an inert gas in a crystalline silicon lattice that has been doped by high doses of krypton and then irradiated by nanosecond laser pulses. The changes in the complex refractive index of this layer induced by laser pulses at different powers are studied. A scanning field ion microscope is used to follow the transformation of the pores, as the energy per unit area of the annealing laser light is varied, and to estimate their sizes. Fiz. Tekh. Poluprovodn. 31, 1130–1134 (September 1997)