Growth of Conductive SrRuO3 Films by Combining Atomic Layer Deposited SrO and Chemical Vapor Deposited RuO2 Layers

SrRuO3 (SRO) film was deposited by sequential executions of atomic layer deposition of SrO and chemical vapor deposition of RuO2 layers at a low growth temperature of 230 degrees C using Sr((Pr3Cp)-Pr-i)(2), RuO4 precursors, and O-2 gas. A wide range of Sr (Ru) concentration could be obtained by modulating the SrO/RuO2 subcycle ratio, and a high growth rate of similar to 2.0 nm/supercycle was achieved with the stoichiometric SRO composition. The as-deposited SRO film was amorphous, and crystallized SRO film was obtained by post deposition annealing in N-2 ambient at temperatures ranging from 600 to 700 degrees C. Crystallized SRO film was adopted as a seed layer for the in situ crystallization of ALD SrTiO3 (STO) film for application to capacitors for next generation dynamic random access memory. Consequently, a crystalline STO film was grown on crystallized SRO in the as-deposited state, and the dielectric constant of the STO film was largely improved compared to that of the amorphous STO, from 12 to 44.