Visualizing the evolution of surface bond straining during radical-surface interactions in plasma deposition processes

Fundamental understanding of radical-surface interactions during plasma deposition of Si thin films is essential for developing rational deposition strategies. We have developed a visualization tool for monitoring the surface bond strain evolution during film growth. This tool is used to examine the local structural changes in the vicinity of the growth surface when a chemical reaction occurs during molecular-dynamics (MD) simulations of Si thin-film deposition and aids in the analysis of radical-surface interactions. Results are presented for the surface bond strain distribution when an SiH₃ radical inserts into an Si-Si dimer on an H-terminated Si(001)-(2 x 1) surface during the initial stage of deposition. This type of analysis is particularly helpful in understanding the reactions and migration of the SiH₃ radical on the surface of plasma-deposited hydrogenated amorphous Si films.