Optical phonons of aluminum nitride

Publisher Website
Google Scholar
Abstract
Oriented polycrystalline films of AlN on Si(111) substrates and amorphous AlN films on sapphire substrates have been prepared by sputter deposition of aluminum in a nitrogen plasma. Phonons at 303, 426, 514, 614, 663, and 831 cm−1 (±3%) have been observed in the Raman spectra of the crystalline films. The 303-cm−1 phonon shifts to 288 cm−1 and the 663-cm−1 phonon to 650 cm−1 in the amorphous sample. By means of infrared absorption measurements with the electric field perpendicular to the c axis we have tentatively identified E1(LO) and E1(TO) modes near 800 and 610 cm−1, respectively. A tentative assignment of the other modes is made from partial data from orientation dependent scattering and results for other wurtzite structure compounds. A comparison of the AlN phonon frequencies with those of other known wurtzite structure compounds shows that Martin’s scaling equation is satisfied.

This publication has 18 references indexed in Scilit: