Ultrathin, Low‐Dissipation Nanomechanical Resonators of Single‐Crystal Diamond

Ultrathin single‐crystal diamond (SCD) resonators offer exceptional potential for high‐performance nanoelectromechanical systems (NEMS), but achieving sub‐100 nm thickness with low dissipation remains a major fabrication challenge. In this work, we develop a smart‐cut‐assisted thinning strategy to reliably fabricate SCD cantilevers with thicknesses down to ~50 nm, representing the thinnest SCD NEMS cantilever achieved to date. Operating from 10 kHz to 3 MHz, these devices exhibit high‐quality factors (∼5 × 10 4 at room temperature and ∼6 × 10 3 at 773 K). The resulting ultrathin resonators exhibit controllable geometries with resonance frequencies that closely follow the Euler–Bernoulli beam model, confirming high structural integrity. The cantilevers demonstrate robust thermal stability, with a low temperature coefficient of frequency of −10 ppm/K. As a result, the ultrathin diamond cantilevers yield a force sensitivity of ∼10 −17 N/Hz 1/2 and a mass resolution of ∼5.89 × 10 −20 kg, close to that of a carbon nanotube cantilever. This work establishes the strategy for batch fabrication of ultrathin SCD NEMS resonators as a highly promising platform for next‐generation high‐sensitivity and robust nanomechanical sensing.