Using Nanometer Platinum Films as Temperature Sensors (Constraints From Experimental, Mathematical, and Finite-Element Analysis)

It has been recognized that metallic films can be used for temperature sensing. It has been recently reported that the relationship between electrical resistance and temperature for thin platinum films (of nanometer size thicknesses) is linear provided that the temperature is below a certain level. However, when temperatures are above this level, the electrical resistance remains relatively constant. To get a better understanding of the properties of these nanometer-sized films, further characterization was performed. This characterization includes mathematical calculations and finite-element analysis to determine the relationships between the thermal properties and the electrical properties. Evaluation of these thin-film sensors shows that the sensitivity (i.e., change in resistance with respect to temperature) is approximately half of the bulk value and the measurement error due to Joule heating should not be an issue.