Initial reaction mechanism of H-passivated Ge surface passivation by atomic layer deposition of A1_2O_3 and A1N

摘要

The authors investigated the surface passivation mechanisms of H-terminated Ge(100)(2 × 1) by atomic layer deposition of A1_2O_3, A1N through first-principles calculation method. The formation of initial A1_2O_3 and A1N passivation layer on Ge surface is investigated at atomic scale and the corresponding reaction pathways for both the reaction are also presented. The reaction barrier heights of H_2O and NH_3 half reaction are 0.53 eV/mol and 0.51 eV/mol higher than that of A1(CH_3)_3 half reaction, respectively which indicates that the overall passivation processes of the both reactions are limited by the second half reaction. Moreover, the chemisorption state and product state of the NH_3 half reaction are found to be in the same energy level, and it is possible that the second half reaction of A1N will be trapped in a chemisorption state.