Molecular dynamics study of the interactions of small thermal and energetic silicon clusters with crystalline and amorphous silicon surfaces

An atomic-scale analysis based on molecular dynamics simulations of the int eractions of small thermal and energetic SinKm, n > 1, clusters observed in various plasmas with crystalline-and amorphous Si surfaces is presented. T he experimental literature has assumed and employed a unit reaction probabi lity for clusters of various sizes on all Si surfaces in phenomenological m odels for obtaining hydrogenated amorphous Si film growth rates, while the reaction mechanisms of clusters with the deposition surfaces have remained unexplored. In addition, it is widely speculated that clusters have a detri mental effect on: the film quality. Our study shows that the clusters react with high (> 85%) probability with crystalline surfaces and with surfaces of amorphous Si films. The structure and energetics of the corresponding ad sorbed cluster configurations on these surfaces are analyzed and discussed. Furthermore, the simulations provide insight into possible mechanisms for the formation of defects, such as voids and dangling bonds, in plasma-depos ited amorphous Si films through reactions of the clusters with the depositi on surfaces. (C) 2001 American Vacuum Society.