Figure 1.

(a) Side view of an aluminum nitride (AlN) contour-mode resonator (CMR), which is formed of top electrodes, an AlN layer, and a bottom electrode. (b–e) The fabrication process consists of a bottom electrode patterning, AlN deposition, top electrode deposition, and the final device release via XeF₂ etching of a silicon layer. (f) A schematic of 220 MHz CMR consisting of the anchor, bus region, top and bottom electrodes, and silicon substrate. The bottom electrode coverage rate is defined as the bottom electrode area (pink) divided by the area where the top electrodes overlap (green).