Study of a piezoresistive cantilever used as a temperature sensing structure in low temperature environments

This paper presents the temperature characteristics of piezoresistive cantilevers in low temperature environments. A thick aluminum film was used as a thermal sensitive material because the thermal expansion coefficient of the aluminum is about 10 times and 50 times larger than the silicon and silicon dioxide respectively. The structure was tested at temperatures ranged from -60 to 40°C and temperature cycling tests were carried out. Each sensitive structure exhibited repeatable performance except the first cycle which indicated an unrecoverable deformation in the first cycle. At lower temperature, the hysteresis became worse. It implied not only the temperature but also the temperature loading process contributed to the sensitive characteristics of the piezoresistive cantilever.