High Performance Polycrystalline Diamond Micro Resonators

The highest Q factors for polycrystalline diamond resonators (also the highest Q factors for a cantilever beam made of any polycrystalline material) have been measured, whose undoped poly-C films grown at 780 degC. For boron doped poly-C films or poly-C films grown at a growth temperature of 600 degC, significantly lower Qs were observed. The doped poly-C film exhibited a peak in dissipation at 673 K, suggesting the existence of a dominant defect in these films that maybe related to boron doping. In addition, the temperature dependence of the poly-C resonators was examined, and a temperature coefficient of resonance frequency in the range of -1.59 x 10^-5 degC^-1 to -2.56 x 10^-5 degC^-1 was observed.