In this paper, we present passive temperature compensation by means of silicon dioxide. Using an oxide refilling technique it avoids gap distance reduction and therefore prevents degradation of electromechanical coupling and motional resistance of the micro-electromechanical resonator. Samples are fabricated and electrically characterized to demonstrate the feasibility of the process concept. A constant quality factor (Q) and only a slight increase of the series resistance value (Rm) are achieved, while the frequency inaccuracy due to temperature variation is reduced. ANSYS simulations are carried out to evaluate the potential of the technique, resulting in a remaining inaccuracy of less than 40ppm.

A novel low-power polysilicon fuse of high reliability was developed. The power consumption is so small that the fuse can be blown with an on-chip circuit. The fuse can be blown with high yield by voltage pulses of an amplitude of approximately 4V and a blowing current of 20–40mA. The fuse is typically blown after 1μs. The total energy consumption amounts to 110nJ. The resistance changes by more than 8 decades. Because of its low-power consumption the fuse can be used to realize an on-chip programmable PROM. This offers the possibility to calibrate chips after mounting and packaging. This paper describes the fuse itself and its application for the calibration of micromechanical sensors after packaging.