Observations of initial growth stage of epitaxial Pb(Zr_,Ti)O_3 thin films on SrTiO_3(1 0 0) substrate by MOCVD

摘要

The initial stage of the metalorganic chemical vapor deposition growth of epitaxial Pb(Zr,Ti)O_3 (PZT) thin films on SrTiO_3(1 0 0) (STO) single-crystal substrates was observed using scanning probe microscopy (SPM). Both annealed and etched STO substrates showed flat surfaces with 100-300 nm wide terraces and atomic-layered steps. SPM observations revealed that the surface of annealed STO substrates was composed of either SrO or TiO_2-terminated terraces and that etched STO substrates consisted of only the TiO_2-terminated surface. PZT films showed the Volmer-Weber (V-M) and Stranski-Krastanov (S-K) growth modes on the SrO and TiO_2-terminated surfaces of STO substrates, respectively.