Bulk micromachined vacuum sensor

In this paper, we present recent work on the fabrication and testing of a silicon bulk micromachined vacuum sensor. The fabrication process, electronics, and various modes of operation are described. The pressure sensitivity is demonstrated between 10/sup -6/ Torr and 10/sup -1/ Torr by "calibrating" against a thermocouple gauge, a capacitance manometer, a spinning rotor gauge, and a hot cathode ionization gauge. For the preferred mode of operation, the frequency dependence on temperature is 0.007 Hz//spl deg/C, the device is vibration insensitive, and has a measured intrinsic Q-factor above 100,000.