RF Oscillators based on Piezoelectric Aluminium Nitride MEMS Resonators

In this paper, piezoelectric aluminium nitride (AlN) MEMS resonators potentially suitable for integrated RF oscillator circuits are studied. The fabrication process yields low-stress AlN layers with strong piezoelectric coupling due to an additional AlN nucleation layer. Electrical RF measurements show quality factors up to 1200 at resonant frequencies up to 400 MHz. For proof-of-concept, a discrete oscillator circuit was designed and successfully manufactured and experimentally characterized.