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Symmetric, peripherally substituted dihydroxysilicon tetrapyrazinoporphyrazines 5 and 6 were synthesized by reacting the diiminoisoindolines 1 and 2 with SiCl₄ in pyridine as solvent at considerably low temperature followed by hydrolysis of the intermediate dichlorosilicon tetrapyrazinoporphyrazines 3 and 4. In addition, the preparation of the bisaxially substituted trialkylsilyloxysilicon tetrapyrazinoporphyrazines 11 and 12, the corresponding trialkylsilyloxyhydroxy compound 14 and the μ-oxo dimer 15 is also reported.

Tetra-2,3-pyridoporphyrazinatosilicon (SiPyD) containing bis(tri-n-hexylsiloxy) (1) or bis(n-heptylcarbonyloxy) (2) axial ligands have been prepared and characterized by NMR, IR and electronic absorption spectroscopies and by thermogravimetric analysis (TGA) and differential thermal analysis (DTA). These SiPyDs are soluble in common organic solvents, and face-to-face-type stacking is prevented in solution and films. Accordingly, their NMR spectra could be reasonably assigned. Their electronic absorption spectra in solution appear to the blue and red compared with those of the corresponding Si phthalocyanines (SiPcs) and Si tetrapyrazinoporphyrazines (SiPyZs) respectively. These characteristics are reproduced by molecular orbital calculations in the framework of the Pariser-Parr-Pople approximation. On formation of films, the Q bands shift to the red of those in solution by ca 20 nm, suggesting that other similar tetravalent metallophthalocyanines with two long axial ligands can be used for shifting the Q band to the red. TGA and DTA experiments show that the thermal stability of the macrocycles is markedly influenced by the type of axial ligands.

We describe the synthesis of tetrasulfonated silicon phthalocyanine and its oligomer product prepared by metal salt catalyzed polycondensation. The catalytic effect of H₂O-free CaCl₂ in quinoline is used for the polycondensation of dihydroxy silicon phthalocyanine to the cofacially arrayed oligomer. Spectroscopic characterization and photoelectron spectroscopy data of the prepared compounds are reported. We present the first results on polypyrrole films doped with these substances.

Elemental distributions of Al, Si, P, S, K, Ca in tea leaves were measured using micro-beam PIXE. In mature tea leaf, aluminum localized eccentrically in the upper epidermis and silicon showed quite similar spatial distribution. It was found that the aluminum concentration and spatial distribution changeed with the growth period of the tea leaf. In younger leaves of two and four month, aluminum showed relatively low concentration compared with the matured one and distributed in mesophyll cell uniformly. In five month leaf, aluminum concentration became higher and the distribution began to localize in upper surface

Silicon levels in dialysis patients are markedly increased. Using PIXE we determined the relationship between silicon concentration and creatinine clearance in 30 samples. Urine silicon concentration were significantly correlated to creatinine clearance (p<0.001). And also serum silicon concentration were significantly correlated to creatinine clearance (p<0.0001).

A 2D hydrodynamic model based on modified Langevin forces for terminal current noise in the RF range is presented for Si and SiGe devices, where all transport and noise parameters are generated by full-band Monte Carlo simulations under bulk conditions and stored in lookup tables. Since these tables have to be built only once, the accuracy of the noise model is improved without increasing the CPU time compared to models based on analytical expressions for the parameters. The accuracy of the noise model is assessed by comparison with the Monte Carlo device model and good agreement of both models is found for diffusion and generation noise. The terminal current noise of a realistic SiGe HBT is investigated and it is found that hole diffusion noise has a strong impact on the collector current noise. The limitations of the thermodynamic model, a compact model for noise, are explored by comparison with the hydrodynamic model.

Recent advances in successful operation of silicon-based devices where transport is dependent on electron magnetic moment, or "spin", could provide a future alternative to CMOS for logic processing. The basics of this spin electronics (Spintronics) technology are discussed and the specific methods necessary for application to silicon are described. Fundamental measurements of spin polarization and spin precession are demonstrated.

Power semiconductor devices are important for numerous applications with power conversion being an important one. Wide energy gap semiconductors SiC and GaN have properties that make them attractive for such applications. Among these properties are high thermal conductivity, high breakdown electric field, wide energy gap, low intrinsic carrier concentration, high thermal stability, high saturation velocity and chemical inertness. These lead to low on-resistance, high breakdown voltage, high frequencies, small volume, and small passive inductors and capacitors. These desirable properties are offset by the higher material costs and higher defect densities. Although wide energy gap devices have been in development for many years, only recently have they become available commercially. Their main competition is silicon power devices with breakdown voltages up to 8000 V and very high surge current capacity. However, silicon power devices are approaching their material limits and wide energy gap devices are beginning to have an impact in the power electronics space. SiC has the advantage of substrates with diameters approaching 150 mm and the ability to grow thermal SiO₂. GaN has the heterojunction advantage, but no viable substrate technology. In fact, a large portion of SiC production is used for GaN substrates. GaN material development has also benefited significantly from the development of optical devices, e.g., light-emitting diodes and lasers.

The economic health of the semiconductor industry requires substantial scaling of chip power, performance, and area with every new technology node that is ramped into manufacturing in two year intervals. With no direct physical link to any particular design dimensions, industry wide the technology node names are chosen to reflect the roughly 70% scaling of linear dimensions necessary to enable the doubling of transistor density predicted by Moore’s law and typically progress as 22nm, 14nm, 10nm, 7nm, 5nm, 3nm etc. At the time of this writing, the most advanced technology node in volume manufacturing is the 14nm node with the 7nm node in advanced development and 5nm in early exploration. The technology challenges to reach thus far have not been trivial. This review addresses the past innovation in response to the device challenges and discusses in-depth the integration challenges associated with the sub-22nm non-planar finFET technologies that are either in advanced technology development or in manufacturing. It discusses the integration challenges in patterning for both the front-end-of-line and back-end-of-line elements in the CMOS transistor. In addition, this article also gives a brief review of integrating an alternate channel material into the finFET technology, as well as next generation device architectures such as nanowire and vertical FETs. Lastly, it also discusses challenges dictated by the need to interconnect the ever-increasing density of transistors.

Studying temperature effects on defect behaviors during thermal annealing is significant for understanding the performance degradation and recovery of semiconductor devices under irradiation. We systematically studied temperature effects on annealing crucial deep-level defects in neutron-irradiated silicon, by developing a multiscale modeling approach. The temperature-dependent concentrations and electron occupation ratios of crucial defects of divacancies (V₂) and tri-vacancies (V₃) were given for dynamic and post-irradiation annealing. Besides the common direct dissociation, we found a new approach to eliminating V₂ and V₃ by their recombination with interstitials dissociated from interstitial-relative defects at relatively low temperatures. To effectively eliminate V₂ and V₃ by post-irradiation annealing, we further determined the activation energies of 1.98eV and 1.71eV for V₂ and V₃, respectively. We also found that, within the operation temperature range of devices, the higher the temperature, the better the radiation resistance. It is thus recommended that the optimal temperature of post-irradiation annealing for device performance recovery is near 600K.

We simulate dopant profiles for phosphorus implantation into silicon using a new model for electronic stopping power. In this model, the electronic stopping power is factorized into a globally averaged effective charge , and a local charge density dependent electronic stopping power for a proton. There is only a single adjustable parameter in the model, namely the one electron radius which controls . By fine tuning this parameter, we obtain excellent agreement between simulated dopant profiles and the SIMS data over a wide range of energies for the channeling case. Our work provides a further example of implant species, in addition to boron and arsenic, to verify the validity of the electronic stopping power model and to illustrate its generality for studies of physical processes involving electronic stopping.

Recent studies are presented demonstrating the important role played by silicon detectors in the discovery of the Higgs boson. CMS is planning to replace it in an extended technical stop of the LHC in the winter of 2016. We present results showing that this replacement will significantly increase the sample of Higgs bosons that will be reconstructed enabling precision studies of this particle.

Previously, the generalized luminosity ℒ was defined and calculated for all incident channels based on an NLC e⁺ e^- design. Alternatives were then considered to improve the differing beam-beam effects in the e^- e^-, eγ and γγ channels. One example was tensor beams composed of bunchlets n_ijk implemented with a laser-driven, silicon accelerator based on micromachining techniques. Problems were considered and expressions given for radiative broadening due to bunchlet manipulation near the final focus to optimize luminosity via charge enhancement, neutralization or bunch shaping. Because the results were promising, we explore fully integrated structures that include sources, optics (for both light and particles) and acceleration in a common format - an accelerator-on-chip. Acceptable materials (and wavelengths) must allow velocity synchronism between many laser and electron pulses with optimal efficiency in high radiation environments. There are obvious control and cost advantages that accrue from using silicon structures if radiation effects can be made acceptable and the structures fabricated. Tests related to deep etching, fabrication and radiation effects on candidate amorphous and crystalline materials show Si(λ_L > 1.2μm) and fused SiO₂(λ_L > 0.3μm) to be ideal materials.

A crystal-chemical study of trioctahedral micas previously characterized by single-crystal XRD has been performed by XANES spectroscopy at the Si and Al K edges. XANES, being a local structural probe, can investigate distortion and modification of the tetrahedral sheet with increasing Fe for Mg substitution in the octahedral sheet. Comparison of XANES spectra allows determining the size of the tetrahedral site occupied by either Si or Al. The Si-O distance remains essentially unchanged whereas the Al-O distance appears to increase. The behavior may be interpreted as a tilt of the tetrahedra, initially rotated to match the ideal mica geometry, with increasing Fe substitution in the octahedral sheet.

Landau-level coincidences are examined in a (100) silicon 2DEG by tuning the valley-splitting with front- and back-gates. A coincidence under quantum Hall conditions between levels of opposite spin, opposite valley, but like orbital indices at ν=6 is found to show suppressed resistance, while in marked contrast, coincidences at ν=4i (where i is an integer) between adjacent orbital Landau levels exhibit resistance spikes.

We have developed a process to grow SrTiO₃ (STO) thin films showing single (110) orientation directly on Si by means of pulsed laser deposition technique. The growth of STO films directly on Si has been described. The crystallinity of the grown STO films was characterized by X-ray diffraction analysis of θ-2θ scan and rocking curve. Our results may be of interest for better understanding of the growth based on the perovskite oxide thin films on silicon materials.

We have examined chemical reactions of small silicon cluster ions for n = 7 - 16 with polar organic molecules M (M = CH₃CN, CD₃OD, C₂H₅CN, and C₂H₅OH). The intensities of the adsorption products for m = 1 and 2 were investigated as a function of n. We found for all polar molecules that the relative intensity of Si_nM⁺ to the unreacted is smaller for n = 11, 13, and 14, that is, the adsorption reactivity is smaller for these n than others. It was also commonly observed that the ion are more intense than neighboring n. We discussed the relationship of the reactivity with the geometrical structures and the stabilities of the bare ions and adsorbed ions, from theoretical calculations based on density functional theory.

The aim of the present work is the optimization of the Si/buffer-layer/YBCO multilayer deposition process so as to grow superconducting films of quality suitable for device applications. The structural properties of the Si/CeO₂ system, obtained by RF magnetron sputtering of CeO₂ targets in Ar atmosphere, have been studied. More than 50 films have been deposited and some of them submitted to post-deposition annealing treatments both in N₂ and O₂ atmospheres. The presence of an unwanted amorphous SiO₂ layer at the Si/CeO₂ interface compromises the YBCO c-axis orientation, and therefore the sharpness of the R versus T transition.

A newly designed deposition system has been realized: it has been specially conceived for obtaining bi- and tri-layers, adopting two targets in YSZ and CeO₂, respectively. Results on YSZ/Si and CeO₂/YSZ/Si systems obtained with the new machine are presented and discussed: (100) oriented YSZ films with nominal thickness of 40 nm have been obtained. The CeO₂ film subsequently deposited has the desired (100) orientation. The YBCO film, in the final YBCO/YSZ/CeO₂/Si configuration, is c-axis oriented.

The deposition of single Si ad-dimer on the p(2×2) reconstructed Si(100) surface has been simulated by an empirical tight-binding (ETB) method. Using the clean and defective Si surfaces as the deposition substrates, the deposition energies are mapped out around the clean surface and dimer vacancies. From the calculated energy plots, the binding sites and several possible diffusion paths are achieved. It is easy for the ad-dimer to form stable state A1 and metal stable state A2 on the clean surface. The change from A1 to A2 state appears as the rotation of the ad-dimer, which has been observed experimentally. The ad-dimers are found to prefer filling into the missing dimer vacancies. Finally, the diffusion traces of the ad-dimers on the surfaces have been simulated.

The chemisorption of one monolayer H atoms on Si(111) surface is studied by using the self-consistent, tight-binding, linear muffin-tin orbital method. Energies of adsorption systems, the layer projected density of states (LPDOS) and charge distributions are calculated. It is found that the adsorbed H atoms are more favorable on the top site with a distance of 0.185 nm above the Si surface. The LPDOS in the clean surface decreases significantly after H adsorption, since the dangling bonds of the surface atoms are partially saturated by the adsorbed H atoms.