Raman spectroscopy was used to characterize the residual stress and defect density of AlN thin films reactively sputtered onto Si (100). The correlation between the shift in the E2 (high) phonon of AlN at 658/cm and the film biaxial stress was studied, and a bi-axial piezospectroscopic coefficient of 3.7cmGPa was obtained. A correlation was found between the width of the Raman line, the O concentration measured by secondary ion mass spectroscopy, and acoustic losses. This laid the basis for the non-destructive assessment of two key thin film properties in micro-electromechanical systems applications: acoustic attenuation and residual stress.

Defect and Stress Characterization of AlN Films by Raman Spectroscopy. V.Lughi, D.R.Clarke: Applied Physics Letters, 2006, 89[24], 241911 (3pp)