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

Abstract

Non-radiative complete surface acoustic wave bandgap for finite-depth holey phononic crystal in lithium niobate Appl. Phys. Lett. 100, 061912 (2012) Investigation of dielectric and electrical properties of Mn doped sodium potassium niobate ceramic system using impedance spectroscopy J. Appl. Phys. 110, 104102 (2011) Determination of depolarization temperature of (Bi1/2Na1/2)TiO3-based lead-free piezoceramics J. Appl. Phys. 110, 094108 (2011) Finite element method simulation of the domain growth kinetics in single-crystal LiTaO3: Role of surface conductivity J. Appl. Phys. 110, 052016 (2011) Additional information on J. Appl. Phys. Thin films of SrTiO 3 were grown by pulsed laser deposition on Si and SiO 2 /Si at 35 and 650°C in a 50 mTorr oxygen discharge ͑300 V͒. The effect of introducing a SiO 2 buffer layer between the Si substrate and the complex oxide on the crystallinity and microstructure of the SrTiO 3 films was investigated at both deposition temperatures. All films grown at 35°C were amorphous. Surface morphology examination by scanning electron microscopy ͑SEM͒ showed that these films were continuous and homogeneous when grown on Si, but were porous and had low-density noninterconnecting lines when grown on SiO 2 /Si. Films prepared at 650°C were polycrystalline and their x-ray-diffraction patterns exhibited peaks corresponding to the ͑001͒, ͑110͒, ͑111͒, and ͑002͒ reflections of the SrTiO 3 cubic phase ͑aϭ3.904 Å͒. The films deposited on SiO 2 /Si were found to grow with a high degree of preferred orientation along the ͑110͒ direction. SEM studies on the surface morphology of the films grown at high temperature showed the presence of a ''rosette'' structure. The mean size of the rosettes was ϳ80 nm in 40-nm-thick films grown on Si and ϳ100 nm in films of similar thickness grown on SiO 2 /Si. Additional atomic force microscopy studies on the topography of these samples indicated that the rosettes were constituted by ϳ35-nm-diam grains. Typical peak-to-valley surface roughness of these films was 0.5-2 nm.

Growth of Highly (100)‐Oriented SrTiO3 Thin Films on Si(111) Substrates Without Buffer Layer

“…[6][7][8] In comparison, the direct growth of STO films on Si(111) substrates without any buffer layer usually provides random-oriented polycrystalline films. 6,9,10 In addition, most of the studies on growing highquality STO films have merely relied on pulsed laser deposition and molecular beam epitaxy. It is therefore worthwhile to simply grow either epitaxial or highly oriented STO films on Si(111) substrates without a buffer layer through a common growth technique.…”

“…Introduction P EROVSKITE SrTiO 3 (STO) has drawn considerable attention in a wide range of electronic applications because of its intriguing physical and electrical properties. 6,9,10 In addition, most of the studies on growing highquality STO films have merely relied on pulsed laser deposition and molecular beam epitaxy. 3 To maximize the quality and performance of STO-based electronic devices, either epitaxial or highly oriented STO films are highly desirable because they are known to offer superior electrical properties, uniformity, and reliability, in comparison with the amorphous and random-oriented polycrystalline films.…”

Nucleation kinetics of SrTiO3 3D islands and nanorings on Si substrates

“…For this reason, the development of new synthetic routes to grow SrTiO 3 nanostructures with good control of the crystal lattice and morphology is of great technological importance. SrTiO 3 thin films have been prepared on Si substrates by several vacuum techniques, such as molecular beam epitaxy (MBE), [10][11][12][13][14][15][16] sputtering, 21 pulsed laser ablation, 22 physical vapour deposition (PVD) 23 and electron-cyclotron-resonance ion beam sputter deposition. 24 A deep understanding on the growth mechanisms, interfacial layer properties and the effect of buffer layers on the structure of SrTiO 3 has been achieved through the use of these techniques.…”

SrTiO[sub 3] Thin Films Deposited by CLCB in Combination with Sol-Gel Processing

“…[1][2][3][4] In addition, they exhibit excellent optical transparency in the visible region, which makes them a promising insulating layer in thin-film electroluminescent displays. 5,6 Various processes including radio-frequency ͑rf͒ sputtering, 7,8 pulsed laser deposition ͑PLD͒, 9,10 molecular beam epitaxy ͑MBE͒, 11 metalorganic chemical vapor deposition ͑MOCVD͒, 12-14 chemical solution deposition ͑CSD͒, 5,15 and sol-gel method 6,16,17 have been used to fabricate ST thin films. Most of these deposition techniques require high-temperature processing conditions (Ͻ600°C) during the deposition or post-annealing processes to obtain vacancy-free crystalline films.…”