Single Crystalline 4H-Sic Membrane Resonators

We report the first wafer-scale fabrication of semi-insulating, single-crystalline 4H-SiC membrane resonators by timed deep reactive ion etch (DRIE). Trenches were etched 184 μm deep with 84.7° sidewall angle to form 16 μm thick suspended membranes. Sidewall angle, DRIE footing, and surface roughness are characterized. Measured resonance frequencies match with COMSOL simulation within 4%. The modes have quality factors of 500 to 1000 at ambient condition.