Characterization of Contour Mode Resonators

In this report, the in uence of several geometric parameters on the performance of aluminum nitride (AlN) contour mode resonators (CMR) is investigated at dierent frequencies (182 MHz, 460 MHz and 570 MHz). Main in uence is the anchor width (Wa) and the anchor length (La), which are expressed as multiples of the acoustic wavelength . The dimensions of the oscillating body will vary as well. It is observed, that during the fabrication one process did not work evenly across the wafer resulting in dierent resonance frequencies of resonators, that should have been identical. The results showed a high standard variance, that might have been due to that. New de-embedding techniques were used during data post processing to compensate elec- trical loads and parasitics. Both applied techniques delivered the same results and improved the quality factor of the resonators up to 20%. From the obtained results, it is concluded that electrical loadings and geometric variations play a bigger role at low frequencies. Phononic crystal structures were used to block elastic waves from propagating through the anchors and thereby reducse the anchor losses. However, no improvement could have been shown.