A SURFACE MICROMACHINED CAPACITIVE ABSOLUTE PRESSURE SENSOR ARRAY ON A GLASS SUBSTRATE

The fabrication process and the characteristics of a new surface micro machined pressure sensor array on a glass substrate are presented. The array consists of electrically parallel individual sensors with compo site SiO2-Cr-SiO2 diaphragms and vacuum-sealed cavities underneath. Th e cavities are created by lateral etching of an Al sacrificial layer. Capacitive sensing of pressure is accomplished via chromic electrodes. The performance of the sensor array is described. In a pressure range of 800 kPa a terminal-based nonlinearity less than 4% was measured fo r the arrays. The pressure sensitivity of the array is about 0.28 fF h Pa(-1).