Magnesium Oxide Films as Temperature Sensor

Abstract

Inexpensive and reliable temperature measurement are important for various applications, including environmental monitoring and control, indoor air conditioning, weather forecasting and automotive and aerospace systems [1-3]. Effort has been made to develop such sensors using thin film technology [4-5]. In general, temperature sensors are used together with flow sensors in order to obtain more accurate data. There are some sensors based on mechanical elements [6-8], but flow sensors based on a thermal mechanism have been studied and developed over the years [5]. Various designs have been examined to improve the properties of such sensors. Flow sensors using a thermal mechanism and resolution is dependent on the sensing material's TCR and resistivity, while accuracy depends on linearity of resistance variation with temperature. Polysilicon films has been extensively investigated as the thermal element need in these sensors, but its temperature response is very non-linear for doped films, making it difficult to attain the required wide temperature range of operation at desired accuracy [2-3]. Pt thin films resistors have been studied for flow sensing and few cases on thin bridge micromechanical structures formed by silicon micromachining were also investigated[1].