Piezoelectrically actuated diamond cantilevers for high-frequency applications

Abstract

In this work, we present a proof-of-concept for the modulation of field emission currents from boron doped nano-diamond based micro-electro-mechanical cantilevers. This modulation was achieved by variations in anode–cathode spacing using mechanical oscillations of the field emitting tips by means of piezoelectric actuation of an aluminum nitride layer. In these devices, the nano-diamond layers serve as a multifunctional material as they are used as field emitters, elastic layers in a unimorph layer stack and as electrodes for piezo-actuation. The cantilevers are processed using conventional micro-fabrication technology and are enhanced by focused ion beam milling, introducing nano-scale features. In addition, it is shown that a stress compensating geometry is efficient to counteract the large thermally induced strain in the nano-materials used.