AIN on silicon based surface acoustic wave resonators operating at 5 GHz

The fabrication and characterisation of surface acoustic wave resonators operating in the gigahertz frequency range are presented. The devices were fabricated on thin AlN layers deposited by magnetron sputtering on high resistivity (100) oriented silicon substrates. Using direct writing e-beam lithography, well defined interdigital transducers with 300 nm finger width and spacing have been obtained. On-wafer microwave measurements have demonstrated a narrow bandstop frequency characteristic with high rejection at approximately 5 GHz and an electromechanical coupling coefficient of 0.53 .