Impact Of Deposition Parameters On The Characterizations Of Highly Orientated Aluminum Nitride For Film Bulk Acoustic Resonator Device

AlN thin films were grown on Si(100) and Al/Si(100) substrates by pulsed dc sputtering system using 99.999% purity aluminum as target, and Ar+N2 gas mixture as precursor. The impact of deposition parameters on material properties has been investigated has been investigated. A good correlation between film crytallinity and dc power, as well as gas pressure, was addressed by x-ray diffraction, and verified by scanning electron microscope (SEM). It is found that highly c-axis oriented h-AlN can be obtained at low gas pressure and low deposition rate. For AlN on Al/Si(100) substrate, micro-crack was observed, which was assigned to the large thermal stress between AlN film and Al layer. Crack-free surface has been achieved by reducing the deposition temperature. The deposition mechanism of AlN deposition is discussed.