Study of Microstructure in SrTiO₃/Si by High-resolution Transmission Electron Microscopy

Microstructure in the SrTiO₃/Si system has been studied using high-resolution transmission electron microscopy and image simulations. SrTiO₃ grows heteroepitaxially on Si with the orientation relationship given by (001)_STO//(001)_Si and [100]_STO//[110]_Si. The lattice misfit between the SrTiO₃ thin films and the Si substrate is accommodated by the presence of interfacial dislocations at the Si substrate side. The interface most likely consists of Si bonded to O in SrTiO₃. The alternative presentation of Sr and Si atoms along the interface leads to the formation of 2× and 3× Sr configurations. Structural defects in the SrTiO₃ thin film mainly consist of tilted domains and dislocations.