Enhanced evaporation from a highly strained Si crystal surface

We observed enhanced evaporation from regions of a single crystal silicon s urface subject to very large local strain. The strain was created across na rrow breaks in silicon carbide films produced by change of phase due to ann ealing. The films were grown in an amorphous form on a (111) Si substrate a t 600 degrees C by hydrogen plasma sputtering. Annealing the SiC/Si structu re at temperatures above 850 degrees C, resulted in contraction due to recr ystallization, giving breaks in the film which approximately followed the < 112 > crystal axes of the Si substrate. We found that the silicon immediat ely beneath a break in a film was preferentially removed leaving a deep dit ch. An enhancement of evaporation of at least 2 orders of magnitude and a c orresponding decrease in activation energy were found from the dependence o f the effect on film thickness and annealing temperature. (C) 2000 American Institute of Physics. [S0021-8979(00)00112-2].