Acoustic Actuation Of Suspended Graphene For Linear Excitation Of 2D Nems

In this paper, we present the fabrication of on-chip piezoelectric acoustic actuation for 2D materials. Acoustic actuation is achieved at device level through patterning of aluminum nitride (AlN) thin film at wafer scale. Two piezoelectric stacks consisting of a 100 nm-thick AlN layer sandwiched between 25 nm-thick platinum (Pt) and molybdenum (Mo) electrodes are fabricated close to the suspended 2D material such as graphene. The graphene nanoelectromechanical resonator is first actuated electrostatically using highly doped silicon (Si) back gate. Due to the effect of damping on amplitude, the frequency response curves do not lie on top of each other. Nonetheless, when actuated through the on-chip piezoelectric stack, the various frequency response curves lie on top of each other, indicating a linearly damped system. We also find that the acoustic actuation technique to be less dissipative than the electrostatic one.