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 sil icon lattice that has been doped by high doses of krypton and then irr adiated by nanosecond laser pulses. The changes in the complex refract ive index of this layer induced by laser pulses at different powers ar e studied. A scanning field ion microscope is used to follow the trans formation of the pores, as the energy per unit area of the annealing l aser light is varied, and to estimate their sizes. (C) 1997 American I nstitute of Physics.