Experimental study of electrical conduction in RuO2-based thick resistive films

Effect of composition on the electrical properties of electroformed screen-printed thick film sandwich devices

“…Therefore, the results of the AC properties for the cermet films suggest that a Poole± Frenkel model with tunnelling conduction through the deep localized states in the band gap of the glassy barriers is the dominant conduction process. Mott and Davis (1977) have also proposed a model for the chalcogenide glasses, in which they stated that tunnelling rather than hopping might be considered to be the possible conduction mechanism for the AC conductivity for bulky films of thicknesses 2 m m. The present AC results show good agreement with a combination of tunnelling/non-tunnelling models proposed by a number of coworkers (Osmanu and Yoshiaki 1991, Bobran 1989, Kolek and Kusy 1991, Kusy 1976). …”

“…The various current transport mechanisms in fired thick film resistor layers have been extensively studied (Osmanu and Yoshiaki 1991, Bobran 1989, Pike and Seager 1977. Recent work on the electrical properties of thick film metal± resistor± metal (MRM) devices has suggested that the dominant conduction mechanism within these devices is Poole± Frenkel bulk-limited conduction (Arshak et al 1994(Arshak et al , 1995.…”

An experimental verification of a percolation model for RuO2-glass thick resistive films

“…The decrease in S with decreasing U for small values of U (see the inset of figure 4) is related to the substantial sheet resistance increase with simultaneous constant slope ofA versus U. Both R,(u) and S(u) curves are not convex in the region of U considered thus they cannot be approximated by the power laws typical of percolative behaviour (Bobran 1989, Bobran and. We show below that the model of threecomponent 3~ RRN can explain the characteristics considered with physically acceptable values of the network parameters.…”

“…Great effort has been made by researchers to fit the experimental data by the power laws R a (U -uJ' and S 0: (U -uJX, with x , xc from RRN corresponding to U , U,, the volume fraction and critical volume fraction of conducting component in T m . The values oft from 2 to 7 that have been found for RuOrglass TRFS (Pike 1978, Kusy 1979, Carciaetall983, Inokumaetal1984, Listkiewiczand Kusy 1985, Kubovy 1986, Bobran 1989) are often evidently greater than those predicted by binary percolation theory. Furthermore, some experimental I/f noise data show qualitatively different behaviour as S versus (U -U,) is not monotonic (Kusy 1979, Inokuma er al1985, Bobran 1989).…”

“…The details of the technological process of obtaining pastes and then the appropriate thick resistive films have been presented elsewhere (Bobran 1989). We have measured g RuO, powder (the evaluated mean grain size U = 400 1 ) as a conducting component thesheetresistance R,, therelative l/fnoisepowerspectral density(re1ativenoise) Sand the temperature characteristics of resistance for these composites with prior checking of the potential distributions along the biased TRFS.…”