Surface reaction mechanism of atomic layer deposition of HfO 2 on Ge(1 0 0)-2 × 1: A density functional theory study

Abstract

Density functional theory is employed to investigate atomic layer deposition mechanism of HfO 2 on Ge(1 0 0)-2 × 1 surface. Both the HfCl 4 and H 2O half-reactions proceed through an analogous trapping-mediated mechanism. The neighboring hydroxyl in the reaction of HfCl 4 with two Ge–OH* sites has a major effect on the formation of HfCl 4 adsorbed complex. In addition, both the Ge and Si reaction pathways are qualitatively similar, however, adsorption of HfCl 4 is favorable on Ge than on Si surface hydroxyl sites. By comparison of the reactions of H 2O on the different surfaces, the differences in energy are negligible to alter the reaction mechanism.