Microelectronic bending and pressure sensors

Development of silicon pressure sensors for measurement of low ( 100 mbar) and middle and high pressure ( 60 bar) is reported. The low pressure sensors were built as silicon bending sensors and supplied with a positive temperature coefficient resistance for temperature compensation. Special attention was paid to humidity stability. For higher pressure silicon-diaphragm pressure sensors were developed with a design based on the (111)-surface. The surface design and the two-step backside etch-technology were optimized and stabilized. Pressure sensor elements were constructed and inserted in cases. Environmental tests were carried out and all sensors show satisfactory behavior.