Initial Growth of Epitaxial (001)SrTiO₃ Film Deposited In Situ on (001)YBaCuO/(100)MgO

Abstract

The surface morphology of both YBa2Cu3O y (YBCO) thin film on a MgO substrate and SrTiO3 (STO) thin film on a YBCO film was observed using scanning tunneling microscopy (STM) and low-energy electron diffraction (LEED) methods. These films were deposited by the ArF excimer laser deposition method. The c-axis-oriented YBCO film of 100 nm thickness grew spirally on a (100)MgO substrate in an island growth mode. The heteroepitaxial STO thin film deposited in situ on the YBCO film grew as if they had filled in the steps of the spiral structure of the YBCO thin film at the stage of initial growth, i.e., STO grew in a kink growth mode. The LEED pattern indicates that the film surface coverd with STO was stable against ordinary air, although the thickness of STO thin film was about 1 nm.

SYNTHESIS OF PEROVSKITE BUFFER LAYERS (SrTiO3, LaA1O3) BY LOW AND ATMOSPHERIC PRESSURE SPRAY PYROLYSIS TECHNIQUES

“…Different buffer layers of Y-Zr0 2 , Ce0 2 , SrTi0 3 , LaA10 3 ...have been reported 1 and several techniques have been employed for its preparation, such as pulsed laser evaporation 2 , sputtering 3 , coevaporation 4 , sol-gel processes 5 and chemical vapor deposition 6 . The Aerosol Assisted MetalOrganic Chemical Vapour Deposition (AAMOCVD) at atmospheric pressure, which features a high deposition rate, uniformity of thickness, complete coverage of surface irregularities, allowing compositional control and the deposition over three dimensional devices, wires..., seems to be an appropriate technique for the deposition of these layers 7 ' 8 .…”

Effect of SiO2 buffer layers on the structure of SrTiO3 films grown on silicon by pulsed laser deposition

“…Besides DRAM capacitors, SrTiO 3 has found application as a modificator of the transition temperature of ferroelectric ͑Ba x Sr 1Ϫx ͒TiO 3 , 6 as a buffer layer for high-T c superconductor thin-film growth on silicon, 7 and as an insulator in superconductor-insulatorsuperconductor structures. 8 For all these applications, the preparation of SrTiO 3 thin films using silicon as deposition substrate is of special interest to the eventual compatibility of novel complex oxide-based devices with the existing integrated-circuit ͑IC͒ technology. One of the major difficulties encountered to date has been the formation of a good interface with reproducible electrical properties between silicon and the complex oxide.…”

“…Hitherto, epitaxial films have been grown mainly on SrTiO 3 and MgO substrates with different crystalline orientations, at temperatures between 500 and 760°C. 8,[13][14][15] MgO substrates were used either bare or covered by Pt or YBaCuO buffer layers. The main effect of the substrate was to change the preferred orientation of the deposited film.…”

“…Recently, scanning tunneling microscopy ͑STM͒ measurements of 1-nmthick SrTiO 3 films grown on YBaCuO/MgO showed that the microstructure was entirely determined by the substrate, whose defect structure was reflected on the deposited film. 8 Epitaxial growth has also been achieved on MgO-buffered GaAs ͑100͒ substrates at 780°C. 16 Despite its great technological interest, the existing studies on pulsed laser deposition of SrTiO 3 on silicon substrates are rather scarce.…”

Pulsed laser deposition of

“…A few reports have been published on BTO thin films or other perovskite oxides grown on oxide superconductors by the method of pulsed laser deposition (PLD) [1,2]. In this work, BTO and YBa 2 Cu 3 O 7−x (YBCO) films were deposited in situ by PLD.…”