IN-SITU LOW-TEMPERATURE GROWTH AND ORIENTATION CONTROL IN MOCVD PZT RUO2 THIN-FILM HETEROSTRUCTURES ON SIO2/SI SUBSTRATES/

Pb(Zr0.5Ti0.5)O-3/RuO2 (PZT/RuO2) thin film heterostructures with cont rolled PZT and RuO2 orientation were successfully grown in-situ on SiO 2/(001)Si substrates at 525 degrees C, using metal-organic chemical va por deposition (MOCVD). XRD analysis revealed that the textured orient ation of the PZT films is strongly dependent on the orientation of RuO 2 bottom electrode layers, PZT layers grown on (101)-textured RuO2 exh ibit a predominant (001) orientation, while those grown on (110)-textu red RuO2 present a mixed (001)-(111)-(110) polycrystalline structure. Highly (110)oriented RuO2 layers were grown using relatively high depo sition temperatures and low rates (similar to 350 degrees C and < 3 nm /min, respectively), while (101)-textured RuO2 layers were grown at sl ightly lower temperatures and higher deposition rates than those for ( 110) layers (i.e., similar to 300 degrees C and > 3 nm/min, respective ly). The RuO2 layers exhibited resistivities of 34-40 mu Omega-cm, ave rage grain size of 65+/-15 nm, and surface roughness of 3-10 nm (rms), while the PZT layers were dense with average grain size of 150-250 nm . Ag/PZT (001)/RuO2(101) capacitors exhibited remanent polarization, s aturation polarization, and coercive field of 49.7 mu C/cm(2), 82.5 mu C/cm(2), and 35.0 kv/cm, respectively, while the values for Ag/PZT (0 01-111-110)/RuO2(110) capacitors were 21.5 mu C/cm(2), 35.4 mu C/cm(2) , and 39.0 kv/cm, respectively.