Integrated approach to electrode and AlN depositions for bulk acoustic wave (BAW) devices

This paper investigates the (002) texture of AlN films deposited by reactive pulsed direct current sputtering on Al, Al-Cu, W and Mo metal electrodes. X-Ray diffraction and atomic force microscopy studies show that the AlN texture is dependent on the deposition conditions and nature of the underlayers. A smooth underlayer with a sharp texture represents the best combination of properties. AlN films with a full width at half maximum less than 1.5 have been deposited on the electrodes studied. It is also possible to deposit well-textured electrodes with a roughness less than 2.5 nm. (C) 2003 Elsevier B.V. All rights reserved.