CMOS-compatible capacitive high temperature pressure sensors

摘要

A new surface-micromachined capacitive single chip pressure sensor for high temperature applications using separation by implantation of oxygen (SIMOX) substrates is presented. The production steps are CMOS-compatible and allow on-chip integration of high temperature readout electronics. Measurements have been performed in a temperature range from 50℃ to 340℃. Three different types of sensors have been investigated with a pressure range of 38, 85 and 125 bar. In the temperature range from 50℃ to 250℃, the offset temperature coefficient (TCO) of the sensors is below the measurable accuracy. In the temperature range from 250℃ to 340℃, the TCO falls off to -5000 ppm/℃ due to induced stress of the package. Sensors that are released from the package show a maximum TCO of less than 500 ppm/℃ over the whole temperature range.