  Single-crystal diamond is a promising material for MEMs devices because of
its low mechanical loss, compatibility with extreme environments, and built-in
interface to high-quality spin centers. But its use has largely been limited by
challenges in processing and growth. We demonstrate a wafer bonding-based
technique to form diamond on insulator, from which we make single-crystal
diamond micromechanical resonators with mechanical quality factors as high as
338,000 at room temperature. Variable temperature measurements down to 10 K
reveal a nonmonotonic dependence of quality factor on temperature. These
resonators enable integration of single-crystal diamond into MEMs technology
for classical and quantum applications.
