Deposition of AlN thin films with cubic crystal structures on silicon substrates at room temperature

Cubic AlN thin films were deposited at room temperature by nitrogen-ion-assisted pulsed laser ablation of a hexagonal AlN target. The full-width at half maximum (FWHM) of the X-ray diffraction peak in the θ to approximately 2θ scan can reach a value of 0.27 degrees. In the Raman spectroscopy measurement, a new peak at 2333 cm^-1 originating from cubic AlN polycrystalline was observed. Nitrogen ions not only effectively promote the formation of stable Al-N bonds but also improve the crystal properties of the deposited thin films. A nitrogen ion energy of 400 eV is proposed for the thin-film deposition.