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The interlayer adhesion in the multilayered micro-devices is of significant importance for their electronic properties. The scratch adhesion test is applied here using a micro-blade sliding under a linearly increased load, combined with optical and SEM visualization, to study the Al2O3/GR/SiO2/Si and Al2O3/hBN/GR/SiO2/Si stacks. The failure of the interlayers is determined by the critical load at which a sudden change in the coefficient of friction or a jump in the contact acoustic emission signal is observed during the scratch. It was found that the hBN/GR bilayer deposited on SiO2 enhanced significantly (~30%) the critical load of the GR/SiO2 interfacial failure compared to that of the GR monolayer. The adhesion at the upper Al2O3/hBN, hBN/GR and Al2O3/GR layers in the stack was improved by 11–15%, due to the thermal annealing, associated with enhanced solid-state diffusion at the interfaces. While the annealing has insufficient effect on the adhesion at the substrate SiO2/Si layers. The scratch adhesion test was proven here as a suitable fast technique for control on the adhesion between layers in the multilayered structures, in order to be proposed for quality control on the fabrication process and the operational performances of micro-/nano-devices. [ABSTRACT FROM AUTHOR]

Integrating two-dimensional (2D) materials into semiconductor manufacturing lines is essential to exploit their material properties in a wide range of application areas. However, current approaches are not compatible with high-volume manufacturing on wafer level. Here, we report a generic methodology for large-area integration of 2D materials by adhesive wafer bonding. Our approach avoids manual handling and uses equipment, processes, and materials that are readily available in large-scale semiconductor manufacturing lines. We demonstrate the transfer of CVD graphene from copper foils (100-mm diameter) and molybdenum disulfide (MoS2) from SiO2/Si chips (centimeter-sized) to silicon wafers (100-mm diameter). Furthermore, we stack graphene with CVD hexagonal boron nitride and MoS2 layers to heterostructures, and fabricate encapsulated field-effect graphene devices, with high carrier mobilities of up to 4520 cm 2 V − 1 s − 1 . Thus, our approach is suited for backend of the line integration of 2D materials on top of integrated circuits, with potential to accelerate progress in electronics, photonics, and sensing. The existing integration approaches for 2D materials often degrade material properties and are not compatible with industrial processing. Here, the authors devise an adhesive wafer bonding strategy to transfer and stack monolayers, suitable for back end of the line integration of 2D materials. [ABSTRACT FROM AUTHOR]

Thin aluminum oxide layers deposited on silicon by thermal atomic layer deposition can be used to reduce the electronic recombination losses by passivating the silicon surfaces. To activate the full passivation ability of such layers, a post-deposition annealing step at moderate temperatures (≈400 C, duration≈30 min) is required. Such an annealing step is commonly done in an oven in air, nitrogen, or forming gas atmosphere. In this work, we investigate the ability to reduce the duration of the annealing step by heating the silicon wafer with a microwave source. The annealing time is significantly reduced to durations below 1 min while achieving effective minority carrier lifetimes similar or higher to that of conventionally oven-annealed samples. [ABSTRACT FROM AUTHOR]

Abstract. Consider the bounded variable logics L[sup k, sub Infinity omega] (with K variable symbols), and C[sup k, sub Infinity omega] (with k variables in the presence of counting quantifiers Existential quantifier[sup is greater than or equal to m]). These fragments of infinitary logic L[sub Infinity omega] are well known to provide an adequate logical framework for some important issues in finite model theory. This paper deals with a translation that associates equivalence of structures in the k-variable fragments with bisimulation equivalence between derived structures. Apart from a uniform and intuitively appealing treatment of these equivalences, this approach relates some interesting issues for the case of an arbitrary number of variables to the case of just three variables. Invertibility of the invariants for is equivalent to c[sub 3], in particular, would imply a positive answer to the tempting conjecture that fixed-point logic with counting captures Union[sub k] P[sub TIME] Intersection C[sup k, sub Infinity omega]. [ABSTRACT FROM AUTHOR]

Abstract. It is a classical result of Mortimer that L[sup 2], first-order logic with two variables, is decidable for satisfiability. We show that going beyond L[sup 2] by adding any one of the following leads to an undecidable logic: -- very weak forms of recursion, viz. (i) transitive closure operations (ii) (restricted) monadic fixed-point operations -- weak access to cardinalities, through the Hartig (or equicardinality) quantifier -- a choice construct known as Hilbert's epsilon-operator. In fact all these extensions of L[sup 2] prove to be undecidable both for satisfiability, and for satisfiability in finite structures. Moreover most of them are hard for SIGMA[sup 1, sub 1], the first level of the analytical hierachy, and thus have a much higher degree of undecidability than first-order logic. [ABSTRACT FROM AUTHOR]

We consider a class of Lindström extensions of first-order logic which are susceptible to a natural Skolemization procedure. In these logics Ehrenfeucht Mostowski (EM) functors for theories with arbitrarily large models can be obtained under suitable restrictions. Characteristic dependencies between algebraic properties of the quantifiers and the maximal domains of EM functors are investigated. Results are applied to Magidor Malitz logic, L(Q), showing e.g. its Hanf number to be equal to ℶ(ℵ) in the countably compact case. Using results of Baumgartner, the maximal number of isomorphism types of linearly ordered models of regular cardinality is shown to be achieved for theories that admit an EM functor on a typically restricted domain. [ABSTRACT FROM AUTHOR]

We demonstrate a novel concept for operating graphene-based Hall sensors using an alternating current (AC) modulated gate voltage, which provides three important advantages compared to Hall sensors under static operation: (1) The sensor sensitivity can be doubled by utilizing both n- and p-type conductance. (2) A static magnetic field can be read out at frequencies in the kHz range, where the 1/f noise is lower compared to the static case. (3) The off-set voltage in the Hall signal can be reduced. This significantly increases the signal-to-noise ratio compared to Hall sensors without a gate electrode. A minimal detectable magnetic field Bmin down to 290 nT / √ Hz and sensitivity up to 0.55 V/VT was found for Hall sensors working on flexible polyimide (PI) substrates. This clearly outperforms state-of-the-art flexible Hall sensors and is comparable to the values obtained by the best rigid III/V semiconductor Hall sensors. [ABSTRACT FROM AUTHOR]

This paper details a software ecosystem comprising three free and open-source Python packages for processing raw ultrafast electron scattering (UES) data and interactively exploring the processed data. The first package, iris, is graphical user-interface program and library for interactive exploration of UES data. Under the hood, iris makes use of npstreams, an extensions of numpy to streaming array-processing, for high-throughput parallel data reduction. Finally, we present scikit-ued, a library of reusable routines and data structures for analysis of UES data, including specialized image processing algorithms, simulation routines, and crystal structure manipulation operations. In this paper, some of the features or all three packages are highlighted, such as parallel data reduction, image registration, interactive exploration. The packages are fully tested and documented and are released under permissive licenses. [ABSTRACT FROM AUTHOR]

Graphene has been considered as a promising material for opto-electronic devices, because of its tunable and wideband optical properties. In this work, we demonstrate electro-refractive phase modulation in graphene at wavelengths from 1530 to 1570 nm. By integrating a gated graphene layer in a silicon-waveguide based Mach-Zehnder interferometer, the key parameters of a phase modulator like change in effective refractive index, insertion loss and absorption change are extracted. These experimentally obtained values are well reproduced by simulations and design guidelines are provided to make graphene devices competitive to contemporary silicon based phase modulators for on-chip applications. [ABSTRACT FROM AUTHOR]