Interfacial reaction in the growth of epitaxial SrTiO3 thin films on (001) Si substrates

Abstract

The SrTiO 3 / Si interface was investigated by transmission electron microscopy for SrTiO 3 films grown on ͑001͒ Si by molecular-beam epitaxy with different native oxide ͑SiO 2 ͒ removal treatments, and Sr/ Ti flux ratios. The interface and film microstructure were independent of the process used to remove the native oxide, but the interface reactivity was dependent on the Sr/ Ti flux ratio. A low Sr/ Ti flux ratio ͑ϳ0.8͒ resulted not only in a layer of amorphous material at the film/substrate interface but also in the formation of crystalline C49 TiSi 2 precipitates at that interface. These results are consistent with thermodynamic expectations in which it is paramount to maintain separation between TiO 2 and the underlying silicon.

Oxygen vacancy-mediated room-temperature ferromagnetism in insulating cobalt-substituted SrTiO3epitaxially integrated with silicon

“…For compositions 10-40%, the symmetric 2θ−θ scan ( become amorphized and that a thin (~1.5 nm) SiO x layer has also formed. The reason for the loss of crystallinity in the undoped STO layer are still unclear and may be due to either preferential amorphization as a result of the TEM sample preparation [40] or to reaction of the thin STO layer with silicon forming silicates and silicides [41][42].…”

Hetero-epitaxial EuO interfaces studied by analytic electron microscopy

“…In contrast to growth on YAlO 3 , epitaxy of EuO on the technologically relevant substrate silicon is challenging by the propensity of silicon interfaces to form SiO 2 and silicides, 6,20,34,35 and by the much larger lattice mismatch of +5.6 % between (001) EuO and (001) Si. Figure 2 shows HAADF-STEM images of an undoped EuO film grown on a bare (001) Si substrate.…”

Epitaxial growth of CdTe on Si through perovskite oxide buffers

“…1,5,6 After perovskite growth, the perovskite/Si composite substrates were loaded, along with bare GaAs substrates, into another reactor for growth by migration-enhanced epitaxy of ZnTe and CdTe. Samples A1 and B1 were grown side by side using a ZnTe nucleation layer at 390°C, followed by a CdTe layer grown at 470°C.…”