Gallium nitride approach for MEMS resonators with highly tunable piezo-amplified transducers

The properties of a new class of electromechanical resonators based on GaN are presented. By using the two-dimensional electron gas (2-DEG) present at the AlGaN/GaN interface and the piezoelectric properties of this heterostructure, we use the R-HEMT (Resonant High Electron Mobility Transistor) as an active piezoelectric transducer up to 5MHz. In addition to the amplification effect of piezoelectric detection, we show that the active piezoelectric transduction has a strong dependence with the channel mobility that is controlled by a top gate. This allows to envision highly tunable sensors with co-integrated HEMT electronics.