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

The fabrication process and the characteristics of a new surface micromachined pressure sensor array on a glass substrate are presented. The array consists of electrically parallel individual sensors with composite SiO2-Cr-SiO2 diaphragms and vacuum-sealed cavities underneath. The 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 for the arrays. The pressure sensitivity of the array is about 0.28 fF hPa(-1).