Polycrystalline InN thin films prepared by ion-beam-assisted filtered cathodic vacuum arc technique

We report on the fabrication of indium nitride (InN) thin films on silicon (1 0 0) substrates by radio frequency ion-beam-assisted filtered cathodic vacuum arc technique at low temperature. The effects of nitrogen ion energy on the structural properties of InN films have been investigated by X-ray diffraction and Raman spectroscopy. The InN films exhibit polycrystalline wurtzite structure. At nitrogen ion energy of 100 eV, the film shows preferred (0 0 0 2) orientation. The preferred orientation is changed to (101̄1) when the nitrogen ion energy is more than 100 eV. Three Raman-active optical phonons have been clearly identified and assigned to A1(LO) at ∼588 cm-1, E22 at ∼490 cm-1and A1(TO) at ∼449 cm-1of InN films, which confirmed the hexagonal structure of InN.