Pulsed-laser modification of germanium nanoclusters in silicon

Abstract

The effect of pulsed ruby laser radiation on Ge nanoclusters grown on a (100)-oriented Si substrate is studied. The energy density of radiation corresponds to the melting threshold of the Si surface. Changes in the structure of nanoclusters are analyzed by comparing the experimental Raman spectra to those calculated in terms of Born-von Karman and Vol’kenstein models. It is established that the action of one pulse changes the cluster size and partly relieves the compression. Still greater changes take place in a sample subjected to ten pulses. The Ge nanoclusters transform into clusters of GexSi1−x solid solution, presumably due to the stress-and vacancy-aided diffusion. Laser-induced thermal processes in germanium nanoclusters in silicon are numerically simulated.