Relationship between residual stress and structural properties of AlN films deposited by r.f. reactive sputtering

Abstract A systematic study of the stress and structural properties of AlN was done as a function of the deposition parameters such as sputtering pressure, target to substrate distance, and nitrogen concentration. As the nitrogen concentration (CN2) decreased, the total pressure (P) and target to substrate distance (d) increased, the residual stress was changed from compressive to tensile stress. The correlation between stress and sputtering conditions was deduced as Pd/CN2 dependency from experimental results. The microstructure of AlN films was also varied by the stress with a little change in crystal orientation. It was found that the compressive stress of AlN films originated from the excess nitrogen content and small-entrapped argon gas by the Rutherford backscattering spectroscopy analysis.