Stiffness-compensated temperature-insensitive micromechanical resonators

Polysilicon /spl mu/mechanical resonators utilizing a novel temperature-dependent electrical stiffness design technique to compensate for temperature-induced frequency shifts have been demonstrated with greatly reduced temperature coefficients (TC/sub f/´s) on the order of -0.24 ppm//spl deg/C, which is 67 times smaller than exhibited by previous uncompensated resonators. With this new resonator design, the total frequency excursion over a 300 K to 380 K range has been reduced from 1,280 ppm for an uncompensated device to only 18 ppm, which for the first time, is now small enough to erase lingering concerns regarding the temperature stability of MEMS-based resonators for use in communication applications.