Frequency tolerance of RF micromechanical disk resonators in polysilicon and nanocrystalline diamond structural materials

A statistical evaluation of the absolute and matching tolerances of the resonance frequencies of surface-micromachined micromechanical 1-port disk resonators is conducted by fabricating and measuring a large quantity (>100) of devices in both polysilicon and nanocrystalline diamond structural materials. Through this analysis, respective average resonance frequency absolute and matching tolerances of 450 ppm and 343 ppm for polysilicon, and 756 ppm and 392 ppm for diamond, have been demonstrated on a measured set of 6 dies on 4-inch wafers fabricated using university facilities. The measured matching tolerance is sufficient to allow implementation of RF pre-select or image-reject filters for wireless communications with a confidence interval better than 99.7% over tested dies without the need for frequency trimming