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  • 1.
    Bakoglidis, Konstantinos D.
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Schmidt, Susann
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Garbrecht, Magnus
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Ivanov, Ivan G.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Halvledarmaterial. Linköpings universitet, Tekniska fakulteten.
    Jensen, Jens
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Greczynski, Grzegorz
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Low-temperature growth of low friction wear-resistant amorphous carbon nitride thin films by mid-frequency, high power impulse, and direct current magnetron sputtering2015Inngår i: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 33, nr 5, artikkel-id 05E112Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Amorphous carbon nitride (a-CNx) thin films were deposited on steel AISI52100 and Si(001) substrates using mid-frequency magnetron sputtering (MFMS) with an MF bias voltage, high power impulse magnetron sputtering (HiPIMS) with a synchronized HiPIMS bias voltage, and direct current magnetron sputtering (DCMS) with a DC bias voltage. The films were deposited at a low substrate temperature of 150 °C and a N2/Ar flow ratio of 0.16 at the total pressure of 400 mPa. The negative bias voltage (Vs) was varied from 20 V to 120 V in each of the three deposition modes. The microstructure of the films was characterized by high-resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED), while the film morphology was investigated by scanning electron microscopy (SEM). All films possessed amorphous microstructure with clearly developed columns extending throughout the entire film thickness. Layers grown with the lowest substrate bias of 20 V exhibited pronounced intercolumnar porosity, independent of the technique used. Voids closed and dense films formed at Vs ≥ 60 V, Vs ≥ 100 V and Vs = 120 V for MFMS, DCMS and HiPIMS, respectively. X-ray photoelectron spectroscopy (XPS) revealed that the nitrogen-to-carbon ratio, N/C, of the films ranged between 0.2 and 0.24. Elastic recoil detection analysis (ERDA) showed that Ar content varied between 0 and 0.8 at% and increases as a function of Vs for all deposition techniques. All films exhibited compressive residual stress, σ, which depends on the growth method; HiPIMS produces the least stressed films with stress between – 0.4 and – 1.2 GPa for all Vs values, while for CNx films deposited by MFMS σ = – 4.2 GPa. Nanoindentation showed a significant increase in film hardness and reduced elastic modulus with increasing Vs for all techniques. The harder films were produced by MFMS with hardness as high as 25 GPa. Low friction coefficients, between 0.05 and 0.06, were recorded for all films. Furthermore, CNx films produced by MFMS and DCMS at Vs = 100 V and 120 V presented a high wear resistance with wear coefficients of k ≤ 2.3 x 10-5 mm3/Nm.

  • 2.
    Chubarov, Mikhail
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska högskolan.
    Pedersen, Henrik
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Kemi. Linköpings universitet, Tekniska högskolan.
    Högberg, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Czigany, Zsolt
    Hungarian Academic Science, Hungary .
    Garbrecht, Magnus
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Henry, Anne
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Polytype pure sp2-BN thin films as dictated by the substrate crystal structure2015Inngår i: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 27, nr 5, s. 1640-1645Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Boron nitride (BN) is a promising semiconductor material, but its current exploration is hampered by difficulties in growth of single crystalline phase-pure thin films. We compare the growth of sp2-BN by chemical vapor deposition on (0001) 6H-SiC and on (0001) α-Al2O3 substrates with an AlN buffer layer. Polytype-pure rhombohedral BN (r-BN) with a thickness of 200 nm is observed on SiC whereas hexagonal BN (h-BN) nucleates and grows on the AlN buffer layer. For the latter case after a thickness of 4 nm, the h-BN growth is followed by r-BN growth to a total thickness of 200 nm. We find that the polytype of the sp2-BN films is determined by the ordering of Si-C or Al-N atomic pairs in the underlying crystalline structure (SiC or AlN). In the latter case the change from h-BN to r-BN is triggered by stress relaxation. This is important for the development of BN semiconductor device technology.

  • 3.
    Elofsson, Viktor
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Nanodesign. Linköpings universitet, Tekniska fakulteten.
    Almyras, Georgios
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Nanodesign. Linköpings universitet, Tekniska fakulteten.
    Lü, Bo
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Nanodesign. Linköpings universitet, Tekniska fakulteten.
    Garbrecht, Magnus
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Boyd, Robert
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Plasma och beläggningsfysik. Linköpings universitet, Tekniska fakulteten.
    Sarakinos, Kostas
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Nanodesign. Linköpings universitet, Tekniska fakulteten.
    Structure formation in Ag-X (X = Au, Cu) alloys synthesized far-from-equilibrium2018Inngår i: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 123, nr 16Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We employ sub-monolayer, pulsed Ag and Au vapor fluxes, along with deterministic growth simulations, and nanoscale probes to study structure formation in miscible Ag-Au films synthesized under far-from-equilibrium conditions. Our results show that nanoscale atomic arrangement is primarily determined by roughness build up at the film growth front, whereby larger roughness leads to increased intermixing between Ag and Au. These findings suggest a different structure formation pathway as compared to the immiscible Ag-Cu system for which the present study, in combination with previously published data, reveals that no significant roughness is developed, and the local atomic structure is predominantly determined by the tendency of Ag and Cu to phase-separate.

  • 4.
    Garbrecht, Magnus
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Schroeder, Jeremy
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska fakulteten.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Birch, Jens
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Saha, Bivas
    University of Calif Berkeley, CA 94720 USA.
    Sands, Timothy D.
    Virginia Tech, VA 24061 USA; Virginia Tech, VA 24061 USA.
    Microstructural evolution and thermal stability of HfN/ScN, ZrN/ScN, and Hf0.5Zr0.5N/ScN metal/semiconductor superlattices2016Inngår i: Journal of Materials Science, ISSN 0022-2461, E-ISSN 1573-4803, Vol. 51, nr 17, s. 8250-8258Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Nitride-based metal/semiconductor superlattices for possible applications as thermoelectric, plasmonic, and hard coating materials have been grown by magnetron sputtering. Since long-time thermal stability of the superlattices is crucial for these applications, the atomic scale microstructure and its evolution under annealing to working temperatures were investigated with high-resolution transmission electron microscopy methods. We report on epitaxial growth of three cubic superlattice systems (HfN/ScN, ZrN/ScN, and Hf0.5Zr0.5N/ScN) that show long-time thermal stability (annealing up to 120 h at 950 degrees C) as monitored by scanning transmission electron microscopy-based energy-dispersive X-ray spectroscopy. No interdiffusion between the metal and semiconductor layers could be observed for any of the present systems under long-time annealing, which is in contrast to earlier attempts on similar superlattice structures based on TiN as the metallic compound. Atomically resolved high-resolution transmission electron microscopy imaging revealed that even though the superlattice curves towards the substrate at regular interval column boundaries originating from threading dislocations close to the substrate interface, the cubic lattice continues coherently across the boundaries. It is found that the boundaries themselves are alloyed along the entire growth direction, while in their vicinity nanometer-size inclusions of metallic phases are observed that could be identified as the zinc blende phase of same stoichiometry as the parent rock salt transition metal nitride phase. Our results demonstrate the longtime thermal stability of metal/semiconductor superlattices based on Zr and Hf nitrides.

  • 5.
    Garbrecht, Magnus
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Spiecker, E.
    University of Kiel, Germany.
    Tillmann, K.
    Forschungszentrum Julich, Germany; Forschungszentrum Julich, Germany.
    Jaeger, W.
    University of Kiel, Germany.
    Quantitative atom column position analysis at the incommensurate interfaces of a (PbS)(1.14)NbS2 misfit layered compound with aberration-corrected HRTEM2011Inngår i: Ultramicroscopy, ISSN 0304-3991, E-ISSN 1879-2723, Vol. 111, nr 3, s. 245-250Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Aberration-corrected HRTEM is applied to explore the potential of NCSI contrast imaging to quantitatively analyse the complex atomic structure of misfit layered compounds and their incommensurate interfaces. Using the (PbS)(1.14)NbS2 misfit layered compound as a model system it is shown that atom column position analyses at the incommensurate interfaces can be performed with precisions reaching a statistical accuracy of +/- 6 pm. The procedure adopted for these studies compares experimental images taken from compound regions free of defects and interface modulations with a structure model derived from XRD experiments and with multi-slice image simulations for the corresponding NCSI contrast conditions used. The high precision achievable in such experiments is confirmed by a detailed quantitative analysis of the atom column positions at the incommensurate interfaces, proving a tetragonal distortion of the monochalcogenide sublattice. (C) 2010 Elsevier B.V. All rights reserved.

  • 6.
    Henry, Anne
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Chubarov, Mikhail
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska fakulteten. Grenoble INP, France.
    Czigany, Zsolt
    Hungarian Academic Science, Hungary.
    Garbrecht, Magnus
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Högberg, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Early stages of growth and crystal structure evolution of boron nitride thin films2016Inngår i: Japanese Journal of Applied Physics, ISSN 0021-4922, E-ISSN 1347-4065, Vol. 55, nr 5, s. 05FD06-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A study of the nucleation and crystal structure evolution at the early stages of the growth of sp(2)-BN thin films on 6H-SiC and alpha-Al2O3 substrates is presented. The growth is performed at low pressure and high temperature in a hot wall CVD reactor, using ammonia and triethylboron as precursors, and H-2 as carrier gas. From high-resolution transmission electron microscopy and X-ray thin film diffraction measurements we observe that polytype pure rhombohedral BN (r-BN) is obtained on 6H-SiC substrates. On alpha-Al2O3 an AlN buffer obtained by nitridation is needed to promote the growth of hexagonal BN (h-BN) to a thickness of around 4 nm followed by a transition to r-BN growth. In addition, when r-BN is obtained, triangular features show up in plan-view scanning electron microscopy which are not seen on thin h-BN layers. The formation of BN after already one minute of growth is confirmed by X-ray photoelectron spectroscopy. (C) 2016 The Japan Society of Applied Physics

  • 7.
    Mak, Wing Cheung
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biosensorer och bioelektronik. Linköpings universitet, Tekniska högskolan.
    Selegård, Robert
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska högskolan.
    Garbrecht, Magnus
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Aili, Daniel
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska högskolan.
    Probing Zinc-Protein-Chelant Interactions using Gold Nanoparticles Functionalized with Zinc-Responsive Polypeptides2014Inngår i: Particle & particle systems characterization, ISSN 0934-0866, E-ISSN 1521-4117, Vol. 31, nr 11, s. 1127-1133Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The coordination of zinc by proteins and various other organic molecules is essential for numerous biological processes, such as in enzymatic catalysis, metabolism and signal transduction. Presence of small molecular chelants can have a profound effect on the bioavailability of zinc and affect critical Zn2+-protein interactions. Zn2+ chelators are also emerging therapeutics for Alzheimer’s diseases because of their preventive effect on zinc promoted amyloid formation. Despite the importance of zinc-protein-chelant interactions in biology and medicine, probing such interactions is  challenging. Here, we introduce an innovative approach for real-time characterization of zinc-protein-chelant interactions using gold nanoparticles (AuNPs) functionalized with a zinc-responsive protein mimetic polypeptide. The peptide functionalized AuNPs aggregate extensively in the presence of Zn2+, triggered by specific Zn2+-mediated polypeptide dimerization and folding, causing a massive red shift of the plasmon band. Chelants affects the Zn2+- polypeptide interaction and thus the aggregation differently depending on their concentrations, zincbinding affinities and coordination numbers, which affect the position of the plasmon band. This system is a simple and powerful tool that provides extensive information about the interactions of chelants in the formation of Zn2+ coordination complexes and is an interesting platform for development of bioanalytical techniques and characterization of chelation-based therapeutics.

  • 8.
    Mikhelashvili, V.
    et al.
    Technion Israel Institute Technology, Israel.
    Meyler, B.
    Technion Israel Institute Technology, Israel.
    Garbrecht, Magnus
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Cohen-Hyams, T.
    Technion Israel Institute Technology, Israel.
    Roizin, Y.
    TowerJazz, Israel.
    Lisiansky, M.
    TowerJazz, Israel.
    Kaplan, W. D.
    Technion Israel Institute Technology, Israel.
    Salzman, Y.
    Technion Israel Institute Technology, Israel.
    Eisenstein, G.
    Technion Israel Institute Technology, Israel.
    The effect of light irradiation on electrons and holes trapping in nonvolotile memory capacitors employing sub 10 nm SiO2-HfO2 stacks and Au nanocrystals2011Inngår i: Microelectronic Engineering, ISSN 0167-9317, E-ISSN 1873-5568, Vol. 88, nr 6, s. 964-968Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We demonstrate the possibility to control charge trapping in the memory stacks comprised of metal nanocrystals (NCs) sandwiched between SiO2 and high-k dielectric films by light irradiation. Non-equilibrium depletion effects in the state of the art charge trapping memories are reported for the first time. The studied nonvolatile memory devices employ Au NCs, thermal SiO2 tunnel layer, atomic layer deposited HfO2 blocking layer and Au/Pt metal gate. The memory windows are 3 V and 10.5 in the dark and under illumination for +/- 10 V programming voltages. Reliability limitations of the studied structure, in particular leakage currents and effects in high electric fields have been investigated in detail and are discussed in view of the mentioned device application. Low programming voltages and currents, and high light sensitivity make suggested NVM structures promising for developing digital imagers with ultralow power consumption. (c) 2011 Elsevier B.V. All rights reserved.

  • 9.
    Mikhelashvili, V.
    et al.
    Technion Israel Institute Technology, Israel.
    Meyler, B.
    Technion Israel Institute Technology, Israel.
    Garbrecht, Magnus
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Yofis, S.
    Technion Israel Institute Technology, Israel.
    Salzman, J.
    Technion Israel Institute Technology, Israel.
    Cohen-Hyams, T.
    Technion Israel Institute Technology, Israel.
    Kaplan, W. D.
    Technion Israel Institute Technology, Israel.
    Roizin, Y.
    TowerJazz, Israel.
    Lisiansky, M.
    TowerJazz, Israel.
    Eisenstein, G.
    Technion Israel Institute Technology, Israel.
    Optical properties of nonvolatile memory capacitors based on gold nanoparticles and SiO2-HfO2 sublayers2011Inngår i: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 98, nr 2, artikkel-id 022905Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We describe the effect of optical excitation of state of the art nonvolatile memory capacitors. The devices comprise Au nanocrystals sandwiched between a SiO2 tunneling layer and a HfO2 blocking layer and exhibit an effective oxide thickness of 7.5 nm. The memory properties are modified by the optical excitation due to nonequilibrium depletion. Optical control with different illumination wavelengths as well as variable optical intensities and pulse widths is described. (C) 2011 American Institute of Physics. [doi:10.1063/1.3543620]

  • 10.
    Mikhelashvili, V.
    et al.
    Technion Israel Institute Technology, Israel.
    Meyler, B.
    Technion Israel Institute Technology, Israel.
    Yoffis, S.
    Technion Israel Institute Technology, Israel.
    Salzman, J.
    Technion Israel Institute Technology, Israel.
    Garbrecht, Magnus
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Cohen-Hyams, T.
    Technion Israel Institute Technology, Israel.
    Kaplan, W. D.
    Technion Israel Institute Technology, Israel.
    Eisenstein, G.
    Technion Israel Institute Technology, Israel.
    A nonvolatile memory capacitor based on Au nanocrystals with HfO2 tunneling and blocking layers2009Inngår i: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 95, nr 2, artikkel-id 023104Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We report on a nonvolatile memory capacitor based on gold nanocrystals serving as charge storage elements located between two HfO2 films acting as the tunneling and control layers. The capacitor has an equivalent oxide thicknesses of 7 nm and exhibits a large hysteresis in the C-V characteristics of 1 and 9 V for gate voltage sweeps of +/- 1 and +/- 7 V, respectively, with no frequency dependence in the range of 10 kHz to 1 MHz. The storage charge density is similar to 1.2x10(13) cm(-2) and the flat band voltage shift is stable for write/erases operations with a voltage swing of +/- 5 V for over 18 h.

  • 11.
    Mikhelashvili, V.
    et al.
    Technion Israel Institute Technology, Israel.
    Meyler, B.
    Technion Israel Institute Technology, Israel.
    Yofis, S.
    Technion Israel Institute Technology, Israel.
    Salzman, J.
    Technion Israel Institute Technology, Israel.
    Garbrecht, Magnus
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Cohen-Hyams, T.
    Technion Israel Institute Technology, Israel.
    Kaplan, W. D.
    Technion Israel Institute Technology, Israel.
    Eisenstein, G.
    Technion Israel Institute Technology, Israel.
    A Nonvolatile Memory Capacitor Based on a Double Gold Nanocrystal Storing Layer and High-k Dielectric Tunneling and Control Layers2010Inngår i: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 157, nr 4, s. H463-H469Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We present a metal-insulator-semiconductor nonvolatile memory capacitor based on two gold nanoparticle charge storage layers, two HfO(2) layers, and a multilayer HfNO/HfTiO stack. The device exhibits an equivalent oxide thickness of 7.3 nm, a hysteresis of 15 V at a gate voltage of +11 to -8 V, and a storage charge density of 2.75x10(13) cm(-2). A leakage of 3.6x10(-5) A/cm(2) at -10 V, a breakdown voltage of 13.3 V, and good retention properties with a hysteresis window of 10 V following more than 10 h of consecutive write/erase operations with a +/- 7 V swing were demonstrated. The capacitor characteristics are frequency-independent in the 10 kHz-1 MHz range.

  • 12.
    Mikhelashvili, V.
    et al.
    Technion Israel Institute Technology, Israel.
    Meyler, B.
    Technion Israel Institute Technology, Israel.
    Yofis, S.
    Technion Israel Institute Technology, Israel.
    Salzman, J.
    Technion Israel Institute Technology, Israel.
    Garbrecht, Magnus
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Cohen-Hyams, T.
    Mikhelashvili, Israel.
    Kaplan, W.
    Mikhelashvili, Israel.
    Eisenstein, G.
    Technion Israel Institute Technology, Israel.
    Nonvolatile Memory Capacitors Based on Double Gold nanocrystals and HfO2 Tunneling and HfNO/HfTiO Laminate Control High-k Insulator Layers.2009Inngår i: PHYSICS AND TECHNOLOGY OF HIGH-K GATE DIELECTRICS 7, Electrochemical Society , 2009, Vol. 25, nr 6, s. 465-471Konferansepaper (Fagfellevurdert)
    Abstract [en]

    We describe all high-k, nonvolatile metal-insulator-semiconductor memory capacitor with an equivalent oxide thickness of 7.3 nm that makes use of two gold nanocrystal charge storage layers. The device exhibits a large memory hysteresis of about 0.75 V and 15 V, respectively at a sweeping gate voltages of +/- 1V and + 11V to -8V with a maximum storage charge density of similar to 2.75x10(13) cm(-2). The leakage current density is 3.6x10(-5) A/cm(2) at -10 V and the breakdown voltage is in the range of 12.3V - 13.3V. A large memory hysteresis window of similar to 10 V was also observed after more than 10 hours of consecutive write / erase operations with a +/- 7 V swing.

  • 13.
    Mikhelashvili, V.
    et al.
    Technion Israel Institute Technology, Israel.
    Meyler, B.
    Technion Israel Institute Technology, Israel.
    Yofis, S.
    Technion Israel Institute Technology, Israel.
    Shneider, Y.
    Technion Israel Institute Technology, Israel.
    Zeidler, A.
    Technion Israel Institute Technology, Israel.
    Garbrecht, Magnus
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Cohen-Hyams, T.
    Technion Israel Institute Technology, Israel.
    Kaplan, W. D.
    Technion Israel Institute Technology, Israel.
    Lisiansky, M.
    TowerJazz, Israel.
    Roizin, Y.
    TowerJazz, Israel.
    Salzman, J.
    Technion Israel Institute Technology, Israel.
    Eisenstein, G.
    Technion Israel Institute Technology, Israel.
    Nonvolatile low-voltage memory transistor based on SiO2 tunneling and HfO2 blocking layers with charge storage in Au nanocrystals2011Inngår i: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 98, nr 21, artikkel-id 212902Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We demonstrate a low voltage nonvolatile memory field effect transistor comprising thermal SiO2 tunneling and HfO2 blocking layers as the gate dielectric stack and Au nanocrystals as charge storage nodes. The structure exhibits a memory window of similar to 2 V at an applied sweeping voltage of +/- 3 V which increases to 12.6 at +/- 12 V. Retention tests show an extrapolated loss of 16% after ten years in the hysteresis width of the threshold voltage. Dynamic program/erase operation reveal an approximately pulse width independent memory for pulse durations of 1 mu s to 10 ms; longer pulses increase the memory window while for pulses shorter than 1 mu s, the memory windows vanishes. The effective oxide thickness is below 10 nm with very low gate and drain leakage currents. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3595484]

  • 14.
    Muhammad, Junaid
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Chen, Yen-Ting
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Palisaitis, Justinas
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Garbrecht, Magnus
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Hsiao, Ching-Lien
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Persson, Per
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Birch, Jens
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Liquid-target Reactive Magnetron Sputter Epitaxy of High Quality GaN(0001ɸ)ɸ Nanorods on Si(111)2015Inngår i: Materials Science in Semiconductor Processing, ISSN 1369-8001, E-ISSN 1873-4081, Vol. 39, s. 702-710Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Direct current magnetron sputter epitaxy with a liquid Ga sputtering target hasbeen used to grow single-crystal GaN(0001) nanorods directly on Si(111)substrates at different working pressures ranging from 5 to 20 mTorr of pure N2,.The as-grown GaN nanorods exhibit very good crystal quality from bottom to topwithout stacking faults, as determined by transmission electron microscopy. Thecrystal quality is found to increase with increasing working pressure. X-raydiffraction results show that all the rods are highly (0001)-oriented. Thenanorods exhibit an N-polarity, as determined by convergent beam electrondiffraction methods. Sharp and well-resolved 4 K photoluminescence peaks at ~3.474 eV with a FWHM ranging from 1.7 meV to 35 meV are attributed to theintrinsic GaN band edge emission and corroborate the superior structuralproperties of the material. Texture measurements reveal that the rods haverandom in-plane orientation when grown on Si(111) with native oxide, while theyhave an in-plane epitaxial relationship of GaN[110] // Si[110] when grown onsubstrates without surface oxide.

  • 15.
    Nijikovsky, Boris
    et al.
    Technion Israel Institute Technology, Israel.
    Richardson, Jacob J.
    University of Calif Santa Barbara, CA 93106 USA.
    Garbrecht, Magnus
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    DenBaars, Steven P.
    University of Calif Santa Barbara, CA 93106 USA.
    Kaplan, Wayne D.
    Technion Israel Institute Technology, Israel.
    Microstructure of ZnO films synthesized on MgAl2O4 from low-temperature aqueous solution: growth and post-annealing2013Inngår i: Journal of Materials Science, ISSN 0022-2461, E-ISSN 1573-4803, Vol. 48, nr 4, s. 1614-1622Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The microstructure of ZnO films synthesized from low-temperature (90 degrees C) aqueous solution on (111) MgAl2O4 single crystal substrates was characterized by X-ray diffraction, high-resolution scanning electron microscopy, conventional and high-resolution transmission electron microscopy. To examine the thermally activated microstructural evolution of the ZnO, both as-deposited and annealed films were characterized. The ZnO films were confirmed to have a ZnO[10 (1) over bar0](0001)parallel to MgAl2O4[011](1 (1) over bar1) orientation relationship, with Zn polarity normal to the surface. Despite their highly oriented nature, the ZnO films have a columnar grain structure with low-angle (less than2.5 degrees) grain boundaries. In addition to lattice dislocations forming low-angle grain boundaries, threading dislocations were observed, emanating from the interface with the substrate. In annealed films, thermally generated voids were observed and appeared to preferentially form at grain boundaries and dislocations. Based on these characterization results, mechanisms are proposed for film growth and microstructural evolution. Finally, the diffusion coefficient of vacancies via dislocations at grain boundaries in the produced ZnO films was estimated.

  • 16.
    Olsson, Simon
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Broitman, Esteban
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Garbrecht, Magnus
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Birch, Jens
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Eriksson, Fredrik
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Mechanical and Tribological Properties of AlCuFe Quasicrystal and Al(Si)CuFe Approximant Thin Films2016Inngår i: Journal of Materials Research, ISSN 0884-2914, E-ISSN 2044-5326, Vol. 31, nr 2, s. 232-240Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Multilayered thin films of Al/Cu/Fe have been prepared by magnetron sputtering and annealed into the quasicrystalline or approximant phases, for Al2O3 or Si substrates, respectively. The nanomechanical and nanotribological properties; hardness, elastic modulus, friction and toughness, have been measured using a triboindenter and analytical methods. The approximant phase, annealed at 600 °C for 4 h, proved to be harder and had higher elastic modulus values than the quasicrystalline phase, about, 15.6 GPa and 258 GPa, respectively. The fracture toughness of the approximant, <0.1 MPa/m½, was however inferior to that of the quasicrystals with 1.5 MPa/m½. The friction coefficients were measured in a range of 0.10-0.14 for the quasicrystalline and approximant thin films.

  • 17.
    Olsson, Simon
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Eriksson, Fredrik
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Jensen, Jens
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Garbrecht, Magnus
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Birch, Jens
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Structure and Composition of Al(Si)CuFe Approximant Thin Films Formed by Si Substrate Diffusion2014Inngår i: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 550, nr 1, s. 105-109Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Multilayered Al/Cu/Fe thin films with composition close to the quasicrystalline phase have been prepared by magnetron sputtering. Annealing at 600 °C yields a homogeneous film of the cubic a-approximant phase by Si substrate diffusion, which prevents the formation of the quasicrystalline phase. After 4 h annealing the film contained 8 at.% Si, which corresponds to the expected value of the a-approximant. The amount of Si in the films was found to slowly increase to ~12 at.% during continued annealing (64 h) while the α-approximant phase was retained. The lattice parameter was found to  continuously decrease as Al became substituted with Si. The film is observed to be polycrystalline with individual grains being strained in varying magnitude, and with no preferential orientation relationship to the substrate or each other.

  • 18.
    Olsson, Simon
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Garbrecht, Magnus
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Birch, Jens
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Eriksson, Fredrik
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Ion-assisted Growth of Quasicrystalline Cu-Al-Sc Directly from the Vapor Phase2013Manuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    Ion assisted depositions have been used to grow the Al38Cu46Sc16 quasicrystalline phase directly from the vapor phase in thin film form. Diffraction experiments reveal that amorphous films are formed at room temperature. The quasicrystalline phase formed at a substrate temperature of 340 °C with an improved quality at higher temperatures up to 460 °C. The quasicrystal film quality is improved by increasing the ion flux during ion-assisted growth with ion energies of 26.7 eV. Increasing the ion energy further was however found to cause resputtering and defects in the film. Electron microscopy reveals a polycrystalline microstructure with crystal grains in the shape of thin needles.

  • 19.
    Olsson, Simon
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Garbrecht, Magnus
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Birch, Jens
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Eriksson, Fredrik
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Phase Evolution of Multilayered Al/Cu/Co Thin Films into Decagonal Al-Cu-Co and Al-Cu-Co-Si Quasicrystalline Phases2013Manuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    Multilayered Al/Cu/Co thin films have been prepared by magnetron sputtering on Al2O3(0001) and Si(001) substrates and the phase evolution has been investigated. The decagonal d-Al-Cu-Co and d-Al-Cu-Co-Si phases were found to form at 500 °C, and at 600 °C these were the only phases. At increasing temperatures, the quasicrystals grew larger in size, up to 500 nm, although always smaller for the d-Al-Cu-Co-Si, and obtained a texturing with the 10-fold periodic axis aligned with the substrate normal. The d-Al-Cu-Co phase persisted to more than 850 °C, with a complete texturing, while the d-Al-Cu-Co-Si phase was replaced by other crystalline phases at 800 °C.

  • 20.
    Saha, Bivas
    et al.
    Purdue University, IN 47907 USA; Purdue University, IN 47907 USA; University of Calif Berkeley, CA 94720 USA.
    Rui Koh, Yee
    Purdue University, IN 47907 USA; Purdue University, IN 47907 USA.
    Comparan, Jonathan
    Purdue University, IN 47907 USA; Purdue University, IN 47907 USA.
    Sadasivam, Sridhar
    Purdue University, IN 47907 USA; Purdue University, IN 47907 USA.
    Schroeder, Jeremy
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska fakulteten.
    Garbrecht, Magnus
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Mohammed, Amr
    Purdue University, IN 47907 USA; Purdue University, IN 47907 USA.
    Birch, Jens
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Fisher, Timothy
    Purdue University, IN 47907 USA; Purdue University, IN 47907 USA.
    Shakouri, Ali
    Purdue University, IN 47907 USA; Purdue University, IN 47907 USA.
    Sands, Timothy D.
    Virginia Tech, VA 24061 USA; Virginia Tech, VA 24061 USA.
    Cross-plane thermal conductivity of (Ti,W)N/(Al,Sc)N metal/semiconductor superlattices2016Inngår i: Physical Review B, ISSN 2469-9950, E-ISSN 2469-9969, Vol. 93, nr 4, s. 045311-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Reduction of cross-plane thermal conductivity and understanding of the mechanisms of heat transport in nanostructured metal/semiconductor superlattices are crucial for their potential applications in thermoelectric and thermionic energy conversion devices, thermal management systems, and thermal barrier coatings. We have developed epitaxial (Ti,W)N/(Al,Sc)N metal/semiconductor superlattices with periodicity ranging from 1 nm to 240 nm that show significantly lower thermal conductivity compared to the parent TiN/(Al, Sc) N superlattice system. The (Ti,W)N/(Al,Sc)N superlattices grow with [001] orientation on the MgO(001) substrates with well-defined coherent layers and are nominally single crystalline with low densities of extended defects. Cross-plane thermal conductivity (measured by time-domain thermoreflectance) decreases with an increase in the superlattice interface density in a manner that is consistent with incoherent phonon boundary scattering. Thermal conductivity values saturate at 1.7W m(-1) K-1 for short superlattice periods possibly due to a delicate balance between long-wavelength coherent phonon modes and incoherent phonon scattering from heavy tungsten atomic sites and superlattice interfaces. First-principles density functional perturbation theory based calculations are performed to model the vibrational spectrum of the individual component materials, and transport models are used to explain the interface thermal conductance across the (Ti,W)N/(Al,Sc)N interfaces as a function of periodicity. The long-wavelength coherent phonon modes are expected to play a dominant role in the thermal transport properties of the short-period superlattices. Our analysis of the thermal transport properties of (Ti,W)N/(Al,Sc)N metal/semiconductor superlattices addresses fundamental questions about heat transport in multilayer materials.

  • 21.
    Schroeder, Jeremy
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Saha, Bivas
    Purdue University, IN 47907 USA; Purdue University, IN 47907 USA.
    Garbrecht, Magnus
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Schell, Norbert
    Helmholtz Zentrum Geesthacht, Germany.
    Sands, Timothy D.
    Virginia Tech, VA 24061 USA; Virginia Tech, VA 24061 USA.
    Birch, Jens
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Thermal stability of epitaxial cubic-TiN/(Al,Sc)N metal/semiconductor superlattices2015Inngår i: Journal of Materials Science, ISSN 0022-2461, E-ISSN 1573-4803, Vol. 50, nr 8, s. 3200-3206Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We report on the thermal stability of epitaxial cubic-TiN/(Al,Sc)N metal/semiconductor superlattices with the rocksalt crystal structure for potential plasmonic, thermoelectric, and hard coating applications. TiN/Al0.72Sc0.28N superlattices were annealed at 950 and 1050 A degrees C for 4, 24, and 120 h, and the thermal stability was characterized by high-energy synchrotron-radiation-based 2D X-ray diffraction, high-resolution (scanning) transmission electron microscopy [HR(S)/TEM], and energy dispersive X-ray spectroscopy (EDX) mapping. The TiN/Al0.72Sc0.28N superlattices were nominally stable for up to 4 h at both 950 and 1050 A degrees C. Further annealing treatments for 24 and 120 h at 950 A degrees C led to severe interdiffusion between the layers and the metastable cubic-Al0.72Sc0.28N layers partially transformed into Al-deficient cubic-(Al,Sc)N and the thermodynamically stable hexagonal wurtzite phase with a nominal composition of AlN (h-AlN). The h-AlN grains displayed two epitaxial variants with respect to c-TiN and cubic-(Al,Sc)N. EDX mapping suggests that scandium has a higher tendency for diffusion in TiN/(Al,Sc)N than titanium or aluminum. Our results indicate that the kinetics of interdiffusion and the cubic-to-hexagonal phase transformation place constraints on the design and implementation of TiN/(Al,Sc)N superlattices for high-temperature applications.

  • 22.
    Spiecker, E.
    et al.
    University of Kiel, Germany.
    Garbrecht, Magnus
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Jaeger, W.
    University of Kiel, Germany.
    Tillmann, K.
    Forschungszentrum Julich, Germany; Forschungszentrum Julich, Germany.
    Advantages of aberration correction for HRTEM investigation of complex layer compounds2010Inngår i: Journal of Microscopy, ISSN 0022-2720, E-ISSN 1365-2818, Vol. 237, nr 3, s. 341-346Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Aberration-corrected high-resolution transmission electron microscopy (HRTEM) has been applied to resolve the atomic structure of a complex layered crystal, (PbS)(1.14)NbS(2), which comprises a high density of incommensurate interfaces. The strong suppression of image delocalization and the favourable contrast transfer under negative C(s) imaging (NCSI) conditions have been exploited for obtaining HRTEM images which directly reveal the projected crystal structure and allow to study lattice imperfections, like stacking disorder and layer undulations, with atomic scale resolution. The advantages of aberration-corrected HRTEM over conventional HRTEM are demonstrated by direct comparison of experimental images and computer simulations.

  • 23.
    Tripathi, J. K.
    et al.
    Tel Aviv University, Israel; Tel Aviv University, Israel.
    Garbrecht, Magnus
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Kaplan, W. D.
    Technion Israel Institute Technology, Israel.
    Markovich, G.
    Tel Aviv University, Israel; Tel Aviv University, Israel.
    Goldfarb, I.
    Tel Aviv University, Israel; Tel Aviv University, Israel; Tel Aviv University, Israel.
    The effect of Fe-coverage on the structure, morphology and magnetic properties of alpha-FeSi2 nanoislands2012Inngår i: Nanotechnology, ISSN 0957-4484, E-ISSN 1361-6528, Vol. 23, nr 49, artikkel-id 495603Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Self-assembled alpha-FeSi2 nanoislands were formed using solid-phase epitaxy of low (similar to 1.2 ML) and high (similar to 21 ML) Fe coverages onto vicinal Si(111) surfaces followed by thermal annealing. At a resulting low Fe-covered Si(111) surface, we observed in situ, by real-time scanning tunneling microscopy and surface electron diffraction, the entire sequence of Fe-silicide formation and transformation from the initially two-dimensional (2 x 2)-reconstructed layer at 300 degrees C into (2 x 2)-reconstructed nanoislands decorating the vicinal step-bunch edges in a self-ordered fashion at higher temperatures. In contrast, the silicide nanoislands at a high Fe-covered surface were noticeably larger, more three-dimensional, and randomly distributed all over the surface. Ex situ x-ray photoelectron spectroscopy and high-resolution transmission electron microscopy indicated the formation of an alpha-FeSi2 island phase, in an alpha-FeSi2{112} parallel to Si{111} orientation. Superconducting quantum interference device magnetometry showed considerable superparamagnetism, with similar to 1.9 mu B/Fe atom at 4 K for the low Fe-coverage, indicating stronger ferromagnetic coupling of individual magnetic moments, as compared to high Fe-coverage, where the calculated moments were only similar to 0.8 mu B/Fe atom. Such anomalous magnetic behavior, particularly for the low Fe-coverage case, is radically different from the non-magnetic bulk alpha-FeSi2 phase, and may open new pathways to high-density magnetic memory storage devices.

  • 24.
    Tripathi, J. K.
    et al.
    Tel Aviv University, Israel.
    Garbrecht, Magnus
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Sztrum-Vartash, Claudia G.
    Tel Aviv University, Israel.
    Rabani, Eran
    Tel Aviv University, Israel; Tel Aviv University, Israel.
    Kaplan, Wayne D.
    Technion Israel Institute Technology, Israel.
    Goldfarb, I.
    Tel Aviv University, Israel; Tel Aviv University, Israel.
    Coverage-dependent self-organized ordering of Co- and Ti-silicide nanoislands along step-bunch edges of vicinal Si(111)2011Inngår i: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 83, nr 16, s. 165409-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We report on self-organized solid-phase epitaxially grown Ti- and Co-silicide nanoislands ordered along step-bunch edges of a vicinal Si(111) surface, as a function of the initial metal (Ti,Co) coverage. While the degree of self-ordering (in terms of step decoration) for Co-silicide islands was higher than for Ti-silicide islands, both types of island had an inverse dependence of the order parameter on coverage. In addition, the positions of the island sites were found to be correlated, and affected by the step-island and island-island interactions, leading to their alignment along the step-bunch less than 110 greater than directions, even for the terrace islands. Aberration-corrected high-resolution transmission electron microscopy was used to characterize the islands crystal structure and growth orientation. The above findings can be understood by the use of coarse-grain modeling.

1 - 24 of 24
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