A noble suspended type thin film resonator (STFR) using the SOI technology

The fabrication and characteristics of suspended type thin film resonators (STFRs) using surface micromachining of the SOI technology, have been studi ed. The size of the active part of STFRs is 160 mum x 160 mum. For the piez oelectric AlN thin film, the following etch rate was observed 200 nm min(-1 ) in 0.6 wt.% TMAH. The thickness of the piezoelectric AlN film for the STF R is 2 mum. Cr thin film is used as the top and bottom electrode. This devi ce is free-standing and has a resonant frequency of 1.65 GHz for the 2 mum AlN thin film, a K-eff(2) of 2.4%, Q(s) of 91.7, Q(p) of 87.7. (C) 2001 Els evier Science B.V. All rights reserved.