Nonlinear dynamics in aluminum nitride contour-mode resonators

Abstract

In this work, we discuss the self-heating nonlinear dynamics of aluminum nitride contour mode resonators. The self-heating introduces a quadratic coupling between the resonator motion and its temperature. This coupling produces a nonlinear frequency response identical to the weakly nonlinear Duffing resonator in steady-state. However, since the thermal relaxation rate is much smaller than the mechanical relaxation rate, the dynamics of the resonator differ from the conventional Duffing resonator.

Methods for precisely controlling the residual stress and temperature coefficient of the frequency of a MEMS resonator based on an AlN cavity silicon-on-insulator platform

“…However, due to the weak capacitive electro-acoustic coupling, most capacitive resonators suffer from high motional impedance and in order to reduce it, the transduction gap needs to be narrow, which brings extra challenge to micro fabrication process and subsequently increases the cost back. In contrast, piezoelectric-based [10][11][12][13][14][15][16][17][18][19][20] resonators can have lower motional impedance and therefore gaining much research attention as well. Researchers have paid a lot of effort to optimize the performance of the resonators, including optimizing the properties of the piezoelectric material [21], controlling the thermal properties of the fabricated resonator [22][23][24][25][26], as well as modelling and optimizing the residual stress and the tip deflection of the stack-layer structures [27][28][29][30][31][32], because residual stress in in various layers of constituting materials can induce large initial static deflection of the cantilever and bring the challenge for the following packaging process by increasing the package thickness.…”

Design and fabrication of aluminum nitride Lamb wave resonators towards high figure of merit for intermediate frequency filter applications

“…Though various techniques have been employed to improve the performance of LWRs, the significance of promoting its R p /R s is not fully recognized. For instance, Piazza et al developed the edge-type AlN LWRs suspended by a pair of tethers [8,9]; Lin et al proposed AIN LWRs with biconvex edges to enhance Q, and they also made contributions to temperature compensation research [10,11]; Yantchev et al introduced grating-type LWRs employing metal as reflective gratings [12,13]. The ratio of R p to R s is typically less than 500, which deteriorates the passband and the roll-off characteristics of the filter.…”

Micro acoustic metamaterials for innovative AlN/AlScN-based RF MEMS

“…As a result, AlScN CMRs's resonance frequency lowers, a phenomenon often referred to as "softening" effect [80,33,63]. The dynamics governing the mechanical motion of CMRs for high driving power levels are well described by those of a mechanical resonator with a Duffing nonlinear term [97] that can be analytically estimated as:…”

“…As a result, using AM anchors reduces the resonators' thermal resistance (R th ) and their Duffing nonlinear coefficient (α d [28,49,97]). A reduction of α d leads to extended linearity in suspended AlN or AlScN devices [63].…”