Limits of quality factor in bulk-mode micromechanical resonators

Abstract

In this paper we present the dominant energy loss mechanisms and quality factor (Q) limits in bulk mode micromechanical resonators. We demonstrate that in resonators with an appropriately designed stem connection to anchor the maximum achievable Q limit is set by either Thermoelastic dissipation (TED) or the Akhieser effect (AKE). Furthermore, we suggest a choice of materials for achieving maximum Q's in micromechanical resonators. It is established here that silicon resonators can theoretically achieve higher Q's than quartz and we predict that by using alternative materials, such as silicon carbide, it is possible to surpass the Q of quartz by more than an order of magnitude.