EPMA and XRD study on nickel metal thin film for temperature sensor

During the measurement and analysis of Micro Total Analysis System (mu-TAS), the bulk of the injected sample is about nano-liter, so that the study of microfluidic sensor has been becoming an important aspect of the analytical instrument. The microfluidic sensor based on the principle of the thermal distribution could be used to measure the micro flow by measuring the asymmetry of temperature profile around the heater. The precision of micro flow measurement depends on the precise of the temperature measurement. Ni thin film was chosen as the material of the temperature sensor, and it was sputtered on different substrates by dc magnetron method. The adhesion between Ni thin film and different substrates were investigated by EPMA (Electron Probe Micro Analyzer). The results indicate that nickel thin film can be used as a suitable material for fabricating temperature sensor, and the arrangement order of the adhesion between Ni thin film and wafer are Si3N4/SiO2/Si, SiO2/Si and Si, respectively. The TCR of the Ni thin film temperature sensor fabricated in this paper is about 6.3 x 10(-3) degrees C-1, which has satisfied the requisition of microfluidic sensor, and it could be used in many fields. (C) 2006 Elsevier B.V. All rights reserved.