Miniaturized Ruthenium Oxide Cryogenic Temperature Sensor Based on MEMS Technology

This paper reports a miniaturized temperature sensor based on ruthenium oxide with low resistance and high sensitivity at cryogenics. The ruthenium oxide thin films were prepared by screen-printing while electrodes were prepared using sputtering and lift-off processes. The size of the bare die is 1.0 mm × 0.8 mm and the packaged device size is 3.0 mm × 2.0 mm utilizing vacuum ceramic packaging technology. Compared with other cryogenic thermometers, this sensor performs a low resistance of 6400 Ω even when the temperature is down to 2 K. While, the temperature sensitivity and temperature coefficient of resistance (TCR) can achieve very high value of -870 Ω/K and -13.5% respectively.