Interfacial and microstructural properties of SrTiO3 thin films grown on Si(001) substrates

Abstract

The microstructure and interfaces of SrTiO 3 thin films directly deposited by metalorganic chemical vapor deposition on silicon ͑001͒ substrates were investigated by means of Bragg-diffraction contrast and high-resolution transmission electron microscopy. The observation of the plan-view specimens showed that the SrTiO 3 films are polycrystalline with randomly oriented grains. An amorphous layer was observed at the interfaces between the films and the substrates. The growth kinetics of this amorphous layer was investigated in detail. The thickness showed a rapid initial increase, which is much faster than the corresponding growth of amorphous SiO 2 in the absence of precursors, and apparently approaches saturation after a short time. The thickness of the interfacial layer increases with the oxygen partial pressure during deposition and a reduction to a value acceptable for gate-oxide applications has been achieved for the minimum pressure given by the oxygen content of the present precursors. However, this comes at the cost of a dramatic increase of the carbon content of the film.

Microstructure and interfaces of HfO2 thin films grown on silicon substrates

“…This saturation behavior, which was also observed in the deposition of HfO 2 with a Hf(NO 3 ) 4 precursor [15] and the deposition of SrTiO 3 on Si(1 0 0) [24], indicates that the interfacial growth is finally controlled by a diffusion-limited mechanism.…”

Magnetoelectric properties of flexible BiFeO3/Ni tapes

“…For instance, an amorphous layer is often observed between the substrate and the film when PLD is used to deposit metal-oxide on Si. 20,21 It should be noted that the chemical information from different regions (see Fig. 1(b)) has also been mapped by EDS, where the sample was prepared by a focused ion beam technique.…”

Resistive switching mechanism of TiO2 thin films grown by atomic-layer deposition

“…The change in the oxidation state of Ti ions in SrTiO 3 single crystals by an applied electric field ͑a few tens of kV/cm͒ at elevated temperatures ͑ϳ500°C͒ has been reported by He et al 18 It seems that the excessively high electric field in the thin-film experiments made the oxygen ions move even at room temperature.…”