A new piezoresistive differential pressure sensor design for harsh wet environments is presented. The sensor design is based on a deposited membrane, which is deposited on top of polysilicon interconnects and piezoresistors. Flat membrane surfaces are thereby achieved. This enables thin film protective coating using sputtered films, which usually have poor step coverage. The concept is demonstrated using both epipoly silicon and sputtered amorphous silicon as membrane materials and tantalum oxide as coating material. Using polysilicon piezoresistors, a sensitivity of 11.3 mV/V bar was obtained. Exposure of the sensors with sputtered amorphous silicon membranes to aggressive media with pH 11 and 70°C for 20 hours did not change their performance.
|Title of host publication||Proceedings of The 14th IEEE International Conference on Micro Electro Mechanical Systems|
|Publication status||Published - 2001|
|Event||14th IEEE International Conference on Micro Electro Mechanical Systems - Interlaken, Switzerland|
Duration: 21 Jan 2001 → 25 Jan 2001
Conference number: 14
|Conference||14th IEEE International Conference on Micro Electro Mechanical Systems|
|Period||21/01/2001 → 25/01/2001|