This project aims at developing high quality factor (Q), large coupling coeffecient (k2) aluminum nitride (AlN) Lamb wave resonators (LWRs) exhibiting low loss and thermally stable performance for wireless communications (e.g. oscillators or filters) in harsh environments. Current technology using thin AlN membrane structures have proved to enable a high phase velocity, low velocity dispersion of the Lamb wave employing the lowest order symmetric mode (S0), thus ensures a high frequency and offers robust designs with low sensitivity to technological tolerances. However, these devices do not allow for open bottom electrode configurations because of the low coupling coefficient, and the existence of the bottom electrode layer brings additional stress especially when temperature rises, which degrades Q and frequency stability. The goal of the thick AlN temperature compensated open bottom electrode LWR project is to develop thermally compensated LWRs with high Q and moderate coupling coefficient working at high temperatures.
Project end date: 01/28/14