Piezoresistive pressure sensors fabricated by surface micromachining process compatible with CMOS process

A piezoresistive pressure sensor has been fabricated with a newly proposed fabrication process, which is quite suitable for fabricating MEMS devices. The fabricated pressure sensors are wire‐bonded and have been tested under the pressure range from 100–1012hPa. The results show that the output voltage increases with the applied pressure. For the structures with membrane length of 800 and 900 µm, the output voltage is linear to the pressure applied and the sensitivity of the sensor is about 0.75 and 0.877mV/hPa. The test results also show that, in order to get a linear output, the membrane length should be less than 1000 µm.