SYNTHESIS OF RUTHENIUM DIOXIDE THIN-FILMS BY A SOLUTION CHEMISTRY TECHNIQUE

Smooth, fine-grained RuO2 thin films have been synthesized and deposit ed onto [100] silicon substrates via a solution chemistry technique. R uthenium(III) chloride n-hydrate dissolved in ethanol was used as the precursor solution. Thin films from a 0.38M solution were spun at 4000 rpm for 20 s onto the substrates and fired at temperatures between 40 0 degrees and 800 degrees C. XRD analysis shows that RuO2 forms over t his entire temperature range. Using an appropriate firing schedule, th e grain growth can be controlled and reproduced to provide for a unifo rm grain size distribution consisting of equiaxed, submicrometer diame ter grains, The electrical resistance of the films has been measured a t 300 K using the conventional four-point probe technique. The resisti vity values range from 1.8 mu Omega . m for the films with an average grain size of 250 nm to 3.1 mu Omega . m for the films with 30 nm grai ns. The presence of residual carbon and hydrogen is not believed to ha ve a significant effect on the resistivity.