High-performance piezoresistive pressure sensors for biomedical applications using very thin structured membranes

High-sensitivity pressure sensors for invasive blood pressure measurements are described. To reduce the unavoidable nonlinearity increase with sensitivity, structured membranes are used. A novel technology based on electrochemical etch-stop and n-diffusions with different junction depths is used to obtain bosses of reduced thicknesses. Based on this technology new structures for pressure sensors have been assessed. The results show that these devices exhibit performances impossible to achieve with classical designs based on flat diaphragms.