Single-crystalline 4H-SiC micro cantilevers with a high quality factor

• We fabricated single-crystalline 4H-SiC cantilevers by electrochemical etching.
• Very sharp resonance was observed for the fabricated 4H-SiC cantilevers.
• The maximum quality factor of 4H-SiC cantilevers is 230,000.
• The quality factor is 10 times higher than that of 3C-SiC cantilevers.

Single-crystalline 4H-SiC micro cantilevers were fabricated by doping-type selective electrochemical etching of 4H-SiC. Using this method, n-type 4H-SiC cantilevers were fabricated on a p-type 4H-SiC substrate, and resonance characteristics of the fabricated 4H-SiC cantilevers were investigated under a vacuum condition. The resonant frequencies agreed very well with the results of numerical simulations. The maximum quality factor in first-mode resonance of the 4H-SiC cantilevers was 230,000. This is 10 times higher than the quality factor of conventional 3C-SiC cantilevers fabricated on an Si substrate.