An Investigation of the Structural and Surface Topography of Aluminum Nitride Thin Films Deposited at Low Sputtering Power for Piezoelectric Applications

Aluminum nitride, a promising piezoelectric material grown below 400°C that is CMOS compatible, can be used for wide piezo applications. In this work, AlN is deposited using reactive magnetron sputtering at sputtering temperature of 300°C. Our focus was to grow c axis-oriented AlN thin-films at relatively low sputtering power for piezoelectric application. In this direction AlN thin films were deposited at a low sputtering power of 100 and 125 W and at a sputtering temperature of 300°С. X-ray diffraction and atomic force microscopy techniques were used to characterize the structural and surface topography of deposited thin films. Films grown at 125 W have a highly c axis-orientation (002) plane with an FWHM value of 0.38°. The roughness of the films was found to be 7.00 Å, and the near zero skewness represents a symmetric roughness distribution in the films. Pure films of this phase can be used for device applications in the future.