Bias dependent specic contact resistance of phase change material to metal contacts

Knowledge of contact resistance of phase change materials (PCM) to metal electrodes is important for scaling, device modeling and optimization of phase change random access memory (PCRAM) cells. In this article, we report the systematic determination of the speci_c contact resistance (_c) with voltage bias for doped Sb2Te to TiW metal electrodes. These data are reported for both the amorphous and the crystalline state of the PCM

Impact of sidewalls on electrical characterization

In this article the impact of sidewalls, formed during reactive ion etching, on the electrical behavior of thin film structures is presented. The presence of sidewalls was experimentally characterized by sheet resistance measurements on Van der Pauw structures. The effect of these sidewalls on the extraction of specific contact resistance from Cross Bridge Kelvin Resistance (CBKR) structures is discussed

An improved method for determining the inversion layer mobility of electrons in trench MOSFETs

For the first time trench sidewall effective electron mobility (/spl mu//sub eff/) values were determined by using the split capacitance-voltage (CV) method for a large range of transversal effective field (E/sub eff/) from 0.1 up to 1.4 MV/cm. The influences of crystal orientation, doping concentration and, for the first time, temperature were investigated. In conclusion, the results show that (1) the split CV method is an accurate method for determining /spl mu//sub eff/(E/sub eff/) data in trench MOSFETs, (2) the {100} /spl mu//sub eff/ data approach published data of planar MOSFETs for high E/sub eff/ and (3) the mobility behavior can be explained with generally accepted scattering models for the entire range of E/sub eff/. The results are important for the optimization of trench power devices

Electrical characterization of Thin-Film structures with redeposited sidewall

Accurate electrical characterization of test structures and devices requires identification and correction for parasitic current paths in the measurement network. The sidewalls formed during reactive ion etching of thin-film phase-change material layers in argon plasma can result in parasitic current paths in the structures. In this paper, thin-film structures with redeposited sidewalls are realized, and they are experimentally characterized by electrical resistance measurements on van der Pauw test structures. The impact of conducting sidewalls on contact resistance measurements and data extraction from cross-bridge Kelvin resistor structures is discussed. The error introduced in the electrical resistance measurements from these test structures is analytically modeled. The impact on the electrical performance of devices due to the formation of sidewalls is also discussed

High-resolution quantification of root dynamics in split-nutrient rhizoslides reveals rapid and strong proliferation of maize roots in response to local high nitrogen

Patches rich in nitrogen are rapidly colonized by selective root growth in maize, which was quantified at high time resolution with state-of-the-art non-invasive imaging techniques in a paper-based growth syste

Doped SbTe phase change material in memory cells

Phase Change Random Access Memory (PCRAM) is investigated as replacement for Flash. The memory concept is based on switching a chalcogenide from the crystalline (low ohmic) to the amorphous (high ohmic) state and vice versa. Basically two memory cell concepts exist: the Ovonic Unified Memory (OUM) and the line cell. Switching to the high ohmic or low ohmic state is done using Joule heating. A relatively short (~ns) electrical pulse with large amplitude is used to heat the crystalline phase to melt and quench into the amorphous state (RESET). A pulse with smaller amplitude heats the amorphous region above its crystallization temperature (lower than the melting temperature) and the material returns into the crystalline state (SET). In the OUM cell this will be at the electrode-phase change material contact, whereas for the line cell this will be at the position where the current density is the highest

Preface

One of the current challenges in plant biology is the development of quantitative phenotyping approaches to link the genotype and the environment to plant structural, functional, and yield characteristics in order to meet the growing demands for sustainable food, feed, and fuel. The genotype of a plant consists of all of the hereditary information within the individual, whilst the phenotype, which represents the morphological, physiological, anatomical, and developmental characteristics, is the result of the interaction between the genotype and the environment. Understanding this interaction is one of the major challenges in plant sciences. In plant breeding, the ultimate goal is the improvement of traits of agricultural importance related to disease resistance, high yields, and the plant’s ability to grow in unfavourable environmental conditions. Currently, breeding approaches produce an annual yield increase of approximately 1% for major crops, which is below the over 2% increase needed to meet the global demands for food by 2050 (Ray et al., 2013).Rapid developments in plant molecular biology and in molecular-based breeding techniques have resulted in an increasing number of species being sequenced and large collections of mutants, accessions, and recombinant lines allowing detailed analysis of gene functions. High-definition genotyping can now be carried out on thousands of plants in an automated way at continuously decreasing costs, thereby facilitating association genetics and the determination of multi-parental quantitative trait loci (QTLs) (Poland and Rife, 2012). For transcriptomic, proteomic, and metabolomic analyses large, often robotized, platforms are available allowing detailed characterization of the biochemical status of plants at a reasonable cost (Ehrhardt and Frommer, 2012). By contrast, an understanding of the link between genotype and phenotype has progressed more slowly and is the major limiting step i