Offset Temperature Characteristics of Silicon Pressure Sensor

The offset voltage drift of silicon pressure sensors is analyzed, assuming that in semiconductor-diffused resistance the variation with temperature is approximated by the 2nd power of temperature. The mechanism of resistance variation from the initial value is investigated and its procedure is displayed in an analytical form. It is found that the internal stress or strain introduced in the various processes from wafer fabrication to bonding and packaging of chips is mainly responsible for the offsed drift. The discussion is also referred to the experiment of bonding, in which the temperature drift is greatly influenced by the thermal stress from the backplate.