Temperature compensation of MEMS resonators using sputtered Fluorine-doped silicon dioxide

In this paper the linear temperature coefficient of frequency in bulk-extensional MEMS resonators is reduced utilizing a relatively thin layer of sputtered Fluorine-doped silicon dioxide (SIOF). The Fluorine doping is achieved through addition of a Fluorine-containing gas in the Ar/O2 gas mixture of a typical SiO2 RF magnetron sputtering process. Our preliminary results indicate that the temperature coefficient of elasticity (TCE) for SIOF could be significantly larger than that of pure SiO2 (1.35X larger) and that the TCE could be tuned by controlling the fluorine concentration in the SIOF film.