Deposition of Conductive Ru and RuO2 Thin Films Employing a Pyrazolate Complex [Ru(CO)3(3,5‐(CF3)2‐pz)]2 as the CVD Source Reagent

Abstract

AbstractThe reaction of Ru3(CO)12 with three equivalent of 3,5‐bis(trifluoromethyl) pyrazole [(3,5‐(CF3)2‐pz)H] at 180 °C produces the double pyrazolate‐bridged ruthenium complex [Ru(CO)3(3,5‐(CF3)2‐pz)]2, (1), in high yield. This ruthenium complex has been characterized by spectroscopic methods, revealing a molecular structure similar to that of the diosmium analogue [Os(CO)3(3,5‐(CF3)2‐pz)]2. Thermogravimetric analysis (TGA) of complex 1 showed an enhanced volatility compared to the parent carbonyl compound Ru3(CO)12 and the closely related, unsaturated 3,5‐di‐tert‐butyl pyrazole complex (2) [Ru2(CO)5(3,5‐t‐Bu2‐pz)2]. Using complex 1 as the CVD source reagent, ruthenium metal with a preferred (002) orientation can be deposited at 400 °C using H2 as the carrier gas. If, however, O2 is used as the carrier gas, RuO2 thin films with a (101) orientation are obtained. The as‐deposited metal thin films were characterized by various surface techniques, as well as by electrical resistivity measurements.