Controlling high-mobility conduction in SrTiO3 by oxide thin film deposition

Abstract

The effect of the top electrode interface on the hysteretic behavior of epitaxial ferroelectric Pb(Zr,Ti)O3 thin films with bottom SrRuO3 electrode J. Appl. Phys. 112, 064116 (2012) Pulsed laser ablation of complex oxides: The role of congruent ablation and preferential scattering for the film stoichiometry Appl. Phys. Lett. 101, 131601 (2012) Applications of pulsed laser ablation for enhanced gold nanofluids J. Appl. Phys. 112, 063113 (2012) Growth processes of lithium titanate thin films deposited by using pulsed laser deposition

Point defect distribution in high-mobility conductiveSrTiO3crystals

“…The transport properties of these samples are dominated by the properties of the STO substrate, which get doped with oxygen vacancies throughout all the volume and indeed display high-mobility conduction ͑typically well above 10 3 cm 2 / V s͒. 9,10 The reduction in the STO substrates scales with the film deposition time and thus, with film thickness. 10 Finally, we have also analyzed an in situ annealed LaAlO 3 ͑LAO͒/STO sample ͑IA-LAO͒.…”

“…9,10 The reduction in the STO substrates scales with the film deposition time and thus, with film thickness. 10 Finally, we have also analyzed an in situ annealed LaAlO 3 ͑LAO͒/STO sample ͑IA-LAO͒. This sample was grown at the same conditions for which a high-mobility conduction was found to be confined within a few unit cells next to the LAO/STO interface ͑see details in Ref.…”

“…7 These studies have proved that vacancies spread over large distances ͑the whole substrate͒ due to the fast diffusion of oxygen vacancies in STO in these growth conditions. [7][8][9][10] While the vacancy concentration can be controlled by the growth time, 10 their spatial distribution is hard to engineer. In this line, low-temperature generation of oxygen vacancies by means of Ar + ion etching of STO surfaces 11,12 has been demonstrated to yield conductive layers at the surface.…”

Metallicity of the SrTiO3 surface induced by room temperature evaporation of alumina

“…• C and above) [1] and during the epitaxial growth of oxides at high temperature by PLD or molecular beam epitaxy under a low oxygen pressure [21,22,20,23]. In this last case, an oxygen transfer occurs from the SrT iO 3 substrate to its oxide overlayer, a mechanism called "autofeeding epitaxy".…”

“…Structural and chemical investigations are now needed in order to precise the nature of the insulating overlayers and the oxygen vacancies distribution in the SrT iO 3 substrate when the evaporation is completed. Whether energetic species or X-rays generated by the e-beam gun play a role in the formation of the oxygen vacancies, like in ion-milling [4] or PLD [20] experiments, has also to be determined. Interestingly enough, a metallic state was recently found when amorphous LaAlO 3 , SrT iO 3 and yttria-stabilized zirconia films are deposited by PLD at room T and under a low oxygen pressure (< 10 −2 mbar) on SrT iO 3 substrates [28].…”