Surface micromachined diaphragm pressure sensors with optimized piezoresistive sensing resistors

Surface micromachined diaphragm pressure sensors utilizing “n” shape piezoresistive sensing resistors have been successfully demonstrated. These micro pressure sensors were fabricated by an integrated process combining both the surface and bulk micromachining techniques. A newly developed design optimization principle was used for the design of the piezoresistive sensing resistors. An absolute type pressure sensor with 100 Psi full scale output was built based on the optimal design principle as well as the integrated micromachining process. Experimental results showed that sensitivity of 0.15 mV/V/Psi, linearity error of ±0.1% FSS (Full Scale Span) and pressure hysteresis of 0.02% FSS has been achieved