A novel capacitive barometric pressure sensor based on the standard CMOS process

A design of barometric pressure sensor is presented in this paper, which is compatible with the standard CMOS process, and can solve the problem of the electrode feed-through out of the sealed cavity at the same time. Both electrodes of the sensor are leaded from the top side of the chip. When the initial gap of both electrodes formed the capacitor is 0.5 μm, and the side length of the square membrane is 710 μm, the sensitivity of 9.4 fF/hPa can be obtained. The nonlinearity of the device is less than 1.02% over a dynamic range 300-500 hPa. It is shown that the device is suitable to be used in measuring the low pressure varying from 300 to 500 hPa, and is more sensitive when the initial gap of the capacitor is smaller.