Experimental-Modeling Framework for Identifying Defects Responsible for Reliability Issues in 2D FETs.

In this work, a self-consistent method is used to identify and describe defects plaguing 300 mm integrated 2D field-effect transistors. This method requires measurements of the transfer characteristic hysteresis combined with physics-based modeling of charge carrier capture and emission processes using technology computer aided design (TCAD) tools. The interconnection of experiments and simulations allows one to thoroughly characterize charge trapping/detrapping by/from defects, depending on their energy position.

Efficient Direct Band-Gap Transition in Germanium by Three-Dimensional Strain.

Complementary to the development of highly three-dimensional (3D) integrated circuits in the continuation of Moore's law, there has been a growing interest in new 3D deformation strategies to improve the device performance. To continue this search for new 3D deformation techniques, it is essential to explore beforehand, using computational predictive methods, which strain tensor leads to the desired properties. In this work, we study germanium (Ge) under an isotropic 3D strain on the basis of first-principles methods.

Variations of paramagnetic defects and dopants in geo-MoS from diverse localities probed by ESR.

Exfoliated flakes from molybdenite crystals often still serve as benchmark substrates for two-dimensional MoS fundamental and device-oriented research. In this article, results are reported of a multi-frequency electron paramagnetic resonance (EPR) study on a series of natural 2H MoS crystals taken from various (seven) geological sites with the intent to explore the variations in quality and properties in terms of occurring paramagnetic point defects, with particular focus on the assessment of the predominant type of impurity dopant. The sample set covers three types of overall doping regimes, i.

Band alignment at interfaces of two-dimensional materials: internal photoemission analysis.

The article overviews experimental results obtained by applying internal photoemission (IPE) spectroscopy methods to characterize electron states in single- or few-monolayer thick two-dimensional materials and at their interfaces. Several conducting (graphene) and semiconducting (transitional metal dichalcogenides MoS, WS, MoSe, and WSe) films on top of thermal SiOhave been analyzed by IPE, which reveals significant sensitivity of interface band offsets and barriers to the details of the material and interface fabrication, indicating violation of the Schottky-Mott rule. This variability is associated with charges and dipoles formed at the interfaces with van der Waals bonding as opposed to the chemically bonded interfaces of three-dimensional semiconductors and metals.

Material-Selective Doping of 2D TMDC through AlO Encapsulation.

For the integration of two-dimensional (2D) transition metal dichalcogenides (TMDC) with high-performance electronic systems, one of the greatest challenges is the realization of doping and comprehension of its mechanisms. Low-temperature atomic layer deposition of aluminum oxide is found to n-dope MoS and ReS but not WS. Based on electrical, optical, and chemical analyses, we propose and validate a hypothesis to explain the doping mechanism.

The origin of negative charging in amorphous AlO films: the role of native defects.

Amorphous aluminum oxide AlO (a-AlO) layers grown by various deposition techniques contain a significant density of negative charges. In spite of several experimental and theoretical studies, the origin of these charges still remains unclear. We report the results of extensive density functional theory calculations of native defects-O and Al vacancies and interstitials, as well as H interstitial centers-in different charge states in both crystalline α-AlO and in a-AlO.

Impact of MoS layer transfer on electrostatics of MoS/SiO interface.

Using internal photoemission of electrons from few-monolayer thin MoS films into SiO we found that the MoS layer transfer processing perturbs electroneutrality of the interface, leading to an increase of the electron barrier height by ≈0.5-1 eV as compared to the case of the same films synthesized directly on SiO. This effect is associated with the formation of an interface dipole, tentatively ascribed to interaction of HO molecules with the SiO surface resulting in the incorporation of silanol (SiOH) groups.

Control of TiN oxidation upon atomic layer deposition of oxides.

The interfaces of a physical-vapor deposited (PVD)-TiN electrode with atomic-layer deposited (ALD) HfO2 layers were studied using photoelectron spectroscopy with high kinetic energies of photoelectrons enabling nondestructive in-depth chemical profiling and phase analysis. Our results reveal the presence of only TiNxOy at the TiN/ALD-HfO2 interface with no measurable traces of the TiO2 phase. By contrast, the interface formed by ALD of HfO2 on top of PVD TiN contains both TiO2 and TiNxOy compounds and may be compared to an HfO2/TiN interface with intentional ALD TiO2 interlayer (IL) formation prior to HfO2 growth.

Intrinsic charge trapping in amorphous oxide films: status and challenges.

We review the current understanding of intrinsic electron and hole trapping in insulating amorphous oxide films on semiconductor and metal substrates. The experimental and theoretical evidences are provided for the existence of intrinsic deep electron and hole trap states stemming from the disorder of amorphous metal oxide networks. We start from presenting the results for amorphous (a) HfO, chosen due to the availability of highest purity amorphous films, which is vital for studying their intrinsic electronic properties.

Intrinsic electron trapping in amorphous oxide.

We demonstrate that electron trapping at intrinsic precursor sites is endemic in non-glass-forming amorphous oxide films. The energy distributions of trapped electron states in ultra-pure prototype amorphous (a)-HfO insulator obtained from exhaustive photo-depopulation experiments demonstrate electron states in the energy range of 2-3 eV below the oxide conduction band. These energy distributions are compared to the results of density functional calculations of a-HfO models of realistic density.

Re-distribution of oxygen at the interface between γ-AlO and TiN.

Interface of TiN electrode with γ-AlO layers was studied using near edge X-ray absorption fine structure, conventional X-ray photoelectron spectroscopy and photoelectron spectroscopy with high energies. Despite the atomic-layer deposited AlO being converted into thermodynamically-stable polycrystalline cubic γ-phase by high-temperature (1000 or 1100 °C) anneal, our results reveal formation of a thin TiNO (≈1-nm thick) interlayer at the interface between γ-AlO film and TiN electrode due to oxygen scavenging from γ-AlO film. Formation of the TiO was not observed at this interface.

Paramagnetic Intrinsic Defects in Polycrystalline Large-Area 2D MoS Films Grown on SiO by Mo Sulfurization.

A low-temperature electron spin resonance study has been carried out on large-area high-purity polycrystalline two-dimensional few monolayer (ML) 2H MoS films synthesized by sulfurization of Mo layers, with intent to atomically assess mobility-degrading detrimental point defects. This reveals the presence of a distinct previously unreported anisotropic defect of axial symmetry about the c-axis characterized by g  = 2.00145 and g  = 2.

Intrinsic point defects in buckled and puckered arsenene: a first-principles study.

Using first-principles calculations, we study the structural, energetic, and electronic properties of various point defects in arsenene. Stone-Wales defects are found to be thermodynamically favorable and are predicted to be stable at room temperature. Defects are found to significantly influence the electronic properties in buckled phase.

Correlation of Bandgap Reduction with Inversion Response in (Si)GeSn/High-k/Metal Stacks.

The bandgap tunability of (Si)GeSn group IV semiconductors opens a new era in Si-technology. Depending on the Si/Sn contents, direct and indirect bandgaps in the range of 0.4-0.

The lead acceptor in p-type natural 2H-polytype MoS crystals evidenced by electron paramagnetic resonance.

A low-temperature (T  =  1.5-8 K) electron paramagnetic resonance study of p-type 2H-polytype natural MoS crystals reveals a previously unreported anisotropic signal of corresponding defect density (spin S  =  ½) ~5  ×  10 cm. For the applied magnetic field B//c-axis, the response is comprised of a single central asymmetric Zeeman peak at zero-crossing g  =  2.

Impact of point defects on the electronic and transport properties of silicene nanoribbons.

We study the impact of various point defects on the structural, electronic and ballistic transport properties of armchair silicene nanoribbons, using the density functional theory and the non equilibrium Green's function method. The effect of a Stone-Wales defect, an interior/edge vacancy and an edge dangling bond is examined. Our results show that structural imperfections can alter the electronic structure (energy band structure and density of states) of the nanoribbons and can either increase or decrease the ballistic current.

Hydrogen-induced rupture of strained Si─O bonds in amorphous silicon dioxide.

Using ab initio modeling we demonstrate that H atoms can break strained Si─O bonds in continuous amorphous silicon dioxide (a-SiO(2)) networks, resulting in a new defect consisting of a threefold-coordinated Si atom with an unpaired electron facing a hydroxyl group, adding to the density of dangling bond defects, such as E' centers. The energy barriers to form this defect from interstitial H atoms range between 0.5 and 1.

[Shockwave lithotripsy in sialolithiasis patients].

Shockwave lithotripsy was performed by various appliances in sialolithiasis patients. The best results were obtained by means of miniature appliances. Lithotripsy proved to be useful safe alternative for sialolithiasis treatment.

[Treatment of significant parotid ducts deformities].

The paper summarizes authors experience in treatment of 14 patients with congenital parotid ducts deformities (megastenon type). The results showed reconstructive surgical treatment to be sufficiently effective in such cases. If restoration of parotid function is not possible one should consider interventions for secretion reduction and duct walls excision.

An electric field tunable energy band gap at silicene/(0001) ZnS interfaces.

The interaction of silicene, the silicon counterpart of graphene, with (0001) ZnS surfaces is investigated theoretically, using first-principles simulations. The charge transfer occurring at the silicene/(0001) ZnS interface leads to the opening of an indirect energy band gap of about 0.7 eV in silicene.

[Correction of immunological reactivity dysregulation syndrome].

Factors, able to cause the second immunodeficit, are very various: sharp and chronic poisonings, protracted reception of some medicinal preparations, chronic stress and overstrain. The general line of the factors described higher is the complex negative affecting all systems of organism, including on the immune system. In addition, such factors as an ionizing radiation is also rendered electoral ingibiruyuschee operating on immunity, related to oppressing of the system of krovetvoreniya.

[Mildronat--treatment of cardio-neurologic pathology in ischemia and hypoxia].

Cerebrovascular pathology has long moved from the category of a single medical problem in the social problem. Progression of vascular lesions of the brain results in significant disability, and in the later stages interfere with the ability to self-service and significantly reduces the quality of life. The key link is ischemic brain damage, or glutamate cascade, which many researchers believe trigger excitotoxic damage and a major cause of neuronal death.

[Correlation of salivary and genital glands].

Based on the experimental data correlation of parotids and genital glands in 24 male rabbits 1.5 months after testectomy (full testectomy, unilateral partial resection and bilateral partial resection) was found out. The findings included hyperplasia, parenchyma atrophy, stromal and periductal sclerosis of the parotids.

[Ultrasound diagnostics in Kuttner syndrome].

The paper describes high-resolution ultrasonic picture of salivary glands in Kuttner syndrome before and after treatment. Ultrasound evaluation proved to be a useful tool for diagnostic, treatment results assessment and choosing adequate treatment option in these patients.