Microelectromechanical system-based vacuum gauge for measuring pressure and outgassing rates in miniaturized vacuum microelectronic devices

Abstract

Cr/Au meander-shaped resistors were fabricated on 0.2 μm thick square-shaped silicon nitride diaphragms with diaphragm dimensions ranging from 0.775 to 2.275 mm. The performance of these sensors was measured in a vacuum chamber as a function of resistor powers from 0.5 to 3 mW at pressures ranging from 2×10−4 to 760 Torr. The lengths of the meander-shaped resistors increase from 5.5 mm for the 0.775 mm diaphragm to 33.6 mm for the 2.275 mm diaphragm devices. It is shown that the pressure dependence of the devices is governed by the kinetic gas theory and that the devices can measure pressures from about 10 to 1×10−3 Torr. At a resistor power of 2 mW at 760 Torr, the 2.275 mm diaphragm device, which has the largest sensing area, exhibits the highest sensitivity.