Adsorption behaviors and crystal structure of AlN films on TiN (001) surfaces by first-principles study

ABSTRACT The initial adsorption behaviors of Al and N atoms on TiN (001) surfaces and the structural stability of rocksalt AlN (rs-AlN) and wurtzite AlN (wz-AlN) films on TiN (001) substrates were calculated by first-principles. The results show that Al atom is adsorbed above N atom of TiN (001) surface initially, and then atomic bondings of Al to N and N to Ti are energetically favorable to form a continuous adsorption. The crystal structure formed by AlN adatoms is investigated by calculating the bonding energy of AlN/TiN interface and strain energy in AlN film. rs-AlN film is inclined to grow on TiN (001) substrate, and it will not transform into the stable wz-AlN structure when the thickness of AlN layer exceeds 8.9 nm or more. This calculation result provides guidance for the preparation of a thick rs-AlN film in the experiments.