  Silicon carbide (SiC) excels in its outstanding mechanical properties, which
are widely studied in Microelectromechanical systems (MEMS). Recently, the
mechanical tuning of color centers in 4H-SiC has been demonstrated, broadening
its application in quantum spintronics. The strain generated in a mechanical
resonator can be used to manipulate the quantum state of the color center
qubit. This work reports a lateral overtone mechanical resonator fabricated
from a semi-insulating (SI) bulk 4H-SiC wafer. An aluminum nitride (AlN)
piezoelectric transducer on SiC is used to drive the resonance. The resonator
shows a series of modes with quality factors (Q) above 3000. An acoustic
reflector positioned at the anchor shows a 22% improvement in the Q at 300 MHz
resonance and suppresses the overtone modes away from it. This monolithic SiC
resonator allows optical access to the SiC color centers from both sides of the
wafer, enabling convenient setup in quantum measurements.
