Thermal sensor properties of cermet resistor films on silicon substrates

Ni-ZrO2 cermet films (similar to1.0 mum thick), with thermal sensitivity su perior to Pt and Ni films, were deposited onto Si substrates using a metall o-organic deposition (MOD) technique. Film structure was developed through controlled, reduced atmosphere sintering at 750 +/- 50 degreesC for 130 min . Resistivity values (rho) for the cermet films (55 +/- 10 vol.% Ni) were i n the range of 2.5 x 10(-4)-6.5 x 10(-2) Omega cm, with linear temperature coefficient of resistance (TCR), i.e. alpha of up to 4200 ppm/degreesC. Fig ure of merit values, defined as the per product in these thermal sensors, w ere of the order of 3 x 10(-6) and up to 1.6 x 10(-4) Omega cm/degreesC for films with rare earth additives. This compares with per of similar to 2.6 X 10(-7) and 4.4 x 10(-8) Omega cm/degreesC for Pt based and Ni films, resp ectively. With these superior sensor properties, the cermet resistor films offer design advantages in size and sensitivity for thermal and flow sensor applications, including low power Joule heating, high gas flow response, a nd high bolometer response to IR radiation. (C) 2001 Elsevier Science B.V. All rights reserved.