Influence of the texture on Raman and X-ray diffraction characteristics of polycrystalline AlN films

The phonon modes of various polycrystalline aluminum nitride (AlN) films deposited by RF reactive sputtering with different textures have been studied. The comparison between Raman spectra and X-ray diffraction (XRD) patterns was performed to find out the influence of the texture on the phonon mode in polycrystalline AlN films. The E-2 (high) mode and the A(1) (TO) mode were observed in Raman scattering along the growth c axis. The orientation and the crystal quality of AlN film have a great impact on the phonon vibration. The deterioration of (002) orientation and the appearance of other orientations on the XRD pattern lead to enhancement of A(1) (TO) mode in the film. The broadening of the Raman peaks can be associated with degeneration in crystal quality. Furthermore, by combining the energy shift of E-2 (high) mode with the measured residual stress, the Raman-stress factor of the polycrystalline AlN films is found to be -4.1 +/- 0.3x10(-9) cm(-1)/Pa for E-2 (high) phonon. (C) 2008 Elsevier B.V. All rights reserved.