Temperature-stable high-Q AlN-on-silicon resonators with embedded array of oxide pillars

Abstract

This paper reports on a new temperature compensation technique for high-Q AlN-on-Silicon bulk acoustic wave resonators. A uniform array of silicon dioxide (SiO2) pillars are formed in the silicon body of the resonator to generate a composite resonator with a near-zero temperature coefficient of frequency (TCF). At a resonance frequency of 24MHz, a total frequency drift of 90 ppm over the temperature range of −20 °C to 100 °C was measured while Q exceeded 10,000 at all temperatures. This compensation technique is applicable to bulk acoustic resonators with thick silicon substrate that demonstrate high Q as well as good power handling and linearity.