Roles of Hydrogen on the Composition and Bonding of Atoms in Hydrogenated Aluminum Nitride Films Prepared by RF Reactive Sputtering

The roles of hydrogen on the composition and bonding of atoms in hydrogenated aluminum nitride (AlN:H) films have been studied. The AlN:H films were prepared by radio frequency (rf) magnetron sputtering of an aluminum target in a mixture of argon, nitrogen, and hydrogen gases. The bonding characteristics of Al, N, O, and H atoms were analyzed by X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. Also, the absolute film composition and the activation energy for the evolution of hydrogen gas from the film were determined by Rutherford backscattering spectrometry and gas chromatography, respectively. With increasing amounts of hydrogen in the gas mixture, the contents of nitrogen increased but those of oxygen decreased in the film because hydrogen facilitates bonding with unbound nitrogen and hinders nitrogen-oxygen bonding. The activation energy for the evolution of hydrogen gas from AlN:H films was found to be 0.11 ± 0.02 eV, implying that the hydrogen in the film formed a hydrogen bond.