Solid phase epitaxy of Ge xSi 1− x films deposited on Si substrates

Abstract

Experimental results concerning the solid-phase epitaxy of e-beam deposited amorphous Ge 0.3Si 0.7 films are presented. The crystallization was performed by annealing either in an open-tube furnace or in a rapid thermal-annealing system, and the crystalline structure was analysed by means of X-ray diffraction. No evidence of crystal growth was observed after annealing at temperatures lower than 750°C by either of the two methods. At 950°C the crystal growth rate was 30 times higher in the rapid thermal annealing system than in the conventional furnace. The relatively high temperatures necessary to promote the epitaxial growth were attributed to the presence of oxygen, an impurity detected in the as-deposited layers by Auger electron spectroscopy. The results indicate that the influence of oxygen on the epitaxy kinetics is less important when rapid thermal annealing, rather than the conventional furnace method, is used.