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The energy band alignment at interfaces between different materials is a key factor, which determines the function of electronic devices. While the energy band alignment of conventional semiconductors is quite well understood, systematic experimental studies on oxides are still missing. This work presents an extensive study on the intrinsic energy band alignment of a wide range of functional oxides using photoelectron spectroscopy with in-situ sample preparation. The studied materials have particular technological importance in diverse fields as solar cells, piezotronics, multiferroics, photoelectrochemistry and oxide electronics. Particular efforts have been made to verify the validity of transitivity, in order to confirm the intrinsic nature of the obtained band alignment and to understand the underlying principles. Valence band offsets up to 1.6 eV are observed. The large variation of valence band maximum energy can be explained by the different orbital contributions to the density of states in the valence band. The framework provided by this work enables the general understanding and prediction of energy band alignment at oxide interfaces, and furthermore the tailoring of energy level matching for charge transfer in functional oxides. (C) 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Many memory candidates based on beyond complementary metal-oxide-semiconductor (CMOS) nanoelectronics have been proposed, but no clear successor has yet been identified. In this paper, we offer a methodology for system-level analysis and address the relationship of the maximum performance of a given memory device type to device physics. The method is illustrated for the classical dynamic RAM (DRAM) device and for the emerging memory device known as the resistive RAM (ReRAM).

Tantalum oxide (TaOx) is an advantageous material system to realize complementary resistive switches, but the ON-window starts to shrink after a few cycles in the voltage sweep mode. A power analysis reveals the presence of power boosts during conventional voltage sweeps in the nonswitching part cell. This power stress is significantly reduced by the use of current sweeps with voltage compliance, leading to very reproducible switching. The endurance is raised to >; 30000 cycles.

A layer stack of strontium ruthenate/strontium titanate/strontium ruthenate was fabricated by low-rate rf sputtering. A high dielectric permittivity of approximately 200 at a capacitive effective thickness of 0.4 nm in combination with a very low leakage current density JC of 5 × 10-9 A/cm2 at 833 kV/cm was achieved. JC is characterized by a Curie-von Schweidler law before current degradation, and stress-induced leakage current sets in. The charge loss due to dielectric absorption showed values below 2% and was evaluated by a transient floating potential setup. From time-dependent dielectric breakdown measurements, we extrapolated an operating lifetime of approximately 7.5 years.

We study the kinetics of bipolar resistive switches in tantalum oxide thin films having different thicknesses. The time to switch from the high resistance state to the low resistance state (SET) is measured repeatedly in a single cell of each sample and analyzed based on a Weibull distribution. In the thin film device the Weibull parameter fJ> 1 is observed in the short time region, followed by a distribution with s 1 mode.

Redox-based nanoionic resistive memory cells are one of the most promising emerging nanodevices for future information technology with applications for memory, logic and neuromorphic computing. Recently, the serendipitous discovery of the link between redox-based nanoionic-resistive memory cells and memristors and memristive devices has further intensified the research in this field. Here we show on both a theoretical and an experimental level that nanoionic-type memristive elements are inherently controlled by non-equilibrium states resulting in a nanobattery. As a result, the memristor theory must be extended to fit the observed non-zero-crossing I–V characteristics. The initial electromotive force of the nanobattery depends on the chemistry and the transport properties of the materials system but can also be introduced during redox-based nanoionic-resistive memory cell operations. The emf has a strong impact on the dynamic behaviour of nanoscale memories, and thus, its control is one of the key factors for future device development and accurate modelling., The original definition of a memristor envisions a two-terminal memory device with a pinched, zero-crossing hysteresis loop. As the authors show here, an electromotive force leads to non-zero-crossing characteristics in nanoionic-type memristors, implying that the memristor definition must be amended.

Booting operating systems over the network is a well established method to simplify system administration in medium to large computer environments. Remote booting Linux and using PXE based environments for large scale system deployments are widely adopted by many system administrators. While scaling very well in controlled subnets they can not easily cross sub-network boundaries or co-exist with each other. Additionally it would be desirable to offer a wider range of standard services not only in dedicated sub-networks but on the whole enterprise infrastructure. This paper discusses advanced network booting methods overcoming the restrictions of traditional PXE/DHCP/TFTP setups. It suggests a new approach combining existing well established boot services into a more flexible framework for remote booting a wide range of operating systems and maintanance tools. A centralized boot configuration web-service is the universal, multi-purpose entry point of the architecture offering configurable, flexible boot menus for directly managed and arbitrary computers of unregistered users.

Using sputter deposition, nonepitaxial ultrathin film capacitors consisting of SrRuO3 electrodes and dielectric SrTiO3 (STO) were grown directly on oxidized silicon substrates. The surface roughness of the layers was found to be very low (

During dynamic random access memory (DRAM) capacitor scaling, a lot of effort was put searching for new material stacks to overcome the scaling limitations of the current material stack, such as leakage and sufficient capacitance. In this study, very promising results for a SrTiO3 based capacitor with a record low capacitance equivalent thickness value of 0.2 nm at target leakage current are presented. Due to the material properties of SrTiO3 films (high vacancy concentration and low band gap), which are leading to an increased leakage current, a physical thickness of at least 8 nm is required at target leakage specifications. However, this physical thickness would not fit into an 18 nm DRAM structure. Therefore, two different new approaches to develop a new ZrO2 based DRAM capacitor stack by changing the inter-layer material from Al2O3 to SrO and the exchange of the top electrode material from TiN to Pt are presented. A combination of these two approaches leads to a capacitance equivalent thickness value...