1992 Volume 112 Issue 12 Pages 736-742
A new micro-pressure-sensor with diaphragm size of 100μm has been fabricated by a surface micromachining technique. A circular diaphragm with 1.6μm in thickness, supported at its edge and center, was adopted to decrease the stress concentration at the diaphragm edge. The diaphragm was formed flat-structure by an etch-stop technique of a polysilicon sacrificial layer. The most suitable arrangement of piezoresistors was determined by FEM (Finite Element Method) stress analysis of the diaphragm. A pressure sensitivity of 20 μV/kPa for a pressure range from 60 to 110 kPa absolute, and a temperature coefficient of the sensitivity of -0.26% F. S./°C for a temperature range from -30 to 85°C were obtained.