Nanocrystalline diamond resonator array for RF signal processing

Two-dimensional arrays of weakly coupled radio frequency (RF) nanomechanical resonators were designed and fabricated in 50–150 nm thick nanocrystalline diamond films using electron beam lithography and dry etch techniques. We present a novel resonator design that allows us to reduce fabrication tolerances and to confine the frequency spread of individual resonators within ∼ 0.6% over the entire modal frequency range up to 100 MHz. Due to an optimized plasma enhanced chemical vapor deposition (PECVD) nanocrystalline diamond deposition process, high quality factors (Q > 8000) have been demonstrated for particular modes of vibrations in single nanomechanical resonators. 2D arrays of coupled resonators exhibit an acoustic band, formed by the splitting of the individual resonant modes. The propagation of a wide-band signal within the array has been demonstrated using a high magnification optical imaging setup with two independently controlled scanning lasers. In order to alleviate various sources of disorder in resonator arrays and to demonstrate their potential for RF signal processing, nanomechanical resonator fabrication techniques and resonator designs will be detailed and compared in this manuscript.