Density functional study of initial HfCl 4 adsorption and decomposition reactions on silicon surfaces with SiON interfacial layer

Abstract

The initial adsorption and decomposition of HfCl 4 on silicon surfaces with different types of SiON interfacial layers are investigated using density functional theory. We find that the reactions of HfCl 4 on both the hydroxylated and nitrided silicon surfaces proceed through similar reaction pathways. By comparison of the reaction energies of HfCl 4 with the hydroxyl and amino surface sites, we find that it is both kinetically and thermodynamically favorable for the reactions of HfCl 4 on hydroxyl site of silicon substrates. Comparing with the adjacent bridging oxygen, we also find that the neighboring hydroxyl can facilitate the adsorption of HfCl 4 on the amido surface site. Also, it is more kinetically and thermodynamically favorable for the reaction of HfCl 4 with bridging NH site than that with NH 2 site.