Reduction of anchor losses by etched slots in aluminum nitride contour mode resonators

Abstract

This paper presents a new technique to increase the quality factor, Q, of AlN Contour Mode Resonators (CMRs). The technique uses etched slots in the body of AlN CMRs to reduce energy dissipation through the anchors. The reduction of the energy lost through the supporting anchors improves the device Q without altering its electromechanical coupling, k <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">t</sub> <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . An almost 50% improvement in the Figure of Merit, FoM, defined as the product between Q and k <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">t</sub> <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , has been measured in 220 MHz AlN CMRs.