Search

Extremely steep switch of negative-capacitance (NC) Nanosheet (NS) GAA-FETs and FinFETs are experimentally presented with $\text{SS}_{\text{avg}}/\text{SS}_{\min}=22/14\text{mV}/\text{dec}$ and $\text{SS}_{\text{avg}}/\text{SS}_{\min}=38/21\ \text{mV}/\text{dec}$ , respectively. The sub-60m V/dec current magnitude of sub-60mV/dec is >4 and ∼5 decades for NC-NSGAA and NC-FinFET, respectively. Both NC-NSGAA and NC-FinFET exhibit extremely steep switch behavior due to FET scale down to nano-scale and comparable domain size of polycrystalline HZO. The dramatic current switch with steep slope is measured with only several dipole domains flipping over with gate voltage applied. The apparent Negative-DIBL and NDR (Negative Differential Resistance) are observed due to strong NC boost. The SS depends on WFin/L ratio, and $\mathrm{W}_{\text{Fin}} is the solution to achieve sub-60m V/dec. The super-steep slope on current behavior still occurs after multiple DC sweep. The uniform size of each NS for stacked NC-NSGAA is an important issue to optimize the NC effect with $\text{SS} =19\text{mV}/\text{dec}$ due to single T NS for capacitance matching by modeling.

InAlN/Al/GaN HEMT directly on Si for steep subthreshold slope (

The typical characteristics of ultra-thin Zr doped in HfO 2 as gate stack is demonstrated. The 1T memory window of P/E retention is 0.67V for 5nm and 1.52V for 7nm after extrapolated 10 years with V P /E=± 4.8V, and >109 cycles of read endurance. It is promising to use ultra-thin FE-HZO as the guidelines for 1T memory applications.

The first experimental demonstration of ferroelectric Al:HfO2 (FE-HAO) FETs is proceeded with negative capacitance (NC) effect. The subthreshold swing (SS) of 40 mV/dec and 39 mV/dec for forward and reverse sweep, respectively, as well as almost hysteresis-free are achieved. The partial orthorhombic phase of FE-HAO is confirmed both with (PMA) and without (PDA) a capping layer. A gradual transition of polarization after 1000°C annealing is obtained with increasing Al concentration for large remanent polarization (P r ), coercive field (E c ), and high dielectric constant. The similar physical thickness (∼7nm) of ferroelectric-HfZrO x (FE-HZO) FET is discussed for comparison. The NC modeling is performed to validate the NC effect for the Al:HfOx material system. The transient behavior is performed at room temperature and low temperature, and the dynamic NC model is discussed.

In this work, three novel TEM methodologies were used to characterize TSVs. First, we utilized the nano-beam diffraction technique to analyze the stress distribution within Si substrates. The keep-out zone can be determined in nano-scale. Second, the hollow-cone dark-field TEM technique was performed to enhance the image contrast of Cu grain features. Third, the TEM/EDS technique was utilized to examine the barrier layer continuity of through silicon TSVs. Both plan-view and cross-sectional view analysis were performed.

In this work, the electron dispersive spectroscopy (EDS) methodology was used to identify the thin stack oxide-nitride oxide (ONO) structure of advanced NAND flash products. By the specific dual silicon drift detectors (SDDs) hardware design and the optimized parameters for data acquisition, the accurate results from a damage-free specimen can be obtained.

Images captured by digital cameras are vulnerable to quality degradations due to non-ideal illumination conditions such as dominated lighting source colors, where images so obtained may not faithfully reproduce the scene chromatics accurately. While it is a complicated process to control the scene illumination, color correction used as a post-processing procedure, is becoming an attractive solution. This research has developed an approach for color correction based on a modified implementation of the gray world assumption. The image color is adjusted by employing a gamma correction to satisfy the gray world assumption and avoid color saturation as encountered in the conventional approach. In order to further improve the image visual quality, an intensity preservation criterion is adopted as an additional means to produce the resultant image. With the normalization of intensity in accordance with the original image, an enhanced image both in color and intensity, is finally obtained. A collection of color images are used in an experiment to verify the proposed algorithm. Results have indicated that the proposed method is effective in producing enhanced images in the context of color enhancements. © 2011 IEEE.

Photonic crystal fiber (PCF) greatly enhances light-matter interactions at path lengths much longer than those in conventional sample cells. The overlap between guided modes and fluid samples introduced into the hollow channels in PCF permits quantitative absorption spectroscopy with small (

Image contrast enhancement is a fundamental and important pre-processing stage in the application of image processing techniques. Among revenues of possible approaches, histogram equalization is a popular and attractive candidate method to produce resultant images of increased contrast. However, images obtained from canonical histogram equalization frequently produce artefacts and give rises to uncomfortable viewing particularly in homogeneous regions. In this work, the problem is tackled using the histogram matching concept where the intensity histogram of the input image is matched to its smoothed version for contrast enhancement. Furthermore, pixel intensities are randomly perturbed for a remedy of artefacts. The resultant image intensities are thus distributed over the available range and an increased image contrast is derived. Satisfactory results are obtained from experiments using a collection of outdoor scenery pictures to verify the effectiveness of the proposed approach. ©2010 IEEE.

Photonic crystal fiber (PCF) has proven very useful for enhancing light-matter interactions, offering interaction lengths much longer than those available using conventional techniques. A well-defined optical mode propagating through a microfluidic channel or gas cell offers a unique way of carrying out absorption spectroscopy in very small sample volumes (∼1 µL) [1–3]. Additional advantages of PCF include its flexibility and the opportunity for system miniaturization. In this paper, we demonstrate the use of hollow-core photonic crystal fiber (HC-PCF) as a highly-controlled (photo)chemical microreactor in which reaction dynamics can be monitored in real-time via broadband spectroscopy. Strong confinement of both sample and light in the core region results in enhanced reaction dynamics and strongly reduced laser power requirements.

Fractal image compression exploits the self-similarity of an image to achieve image compression. The conventional algorithm allows the transformations on domain blocks to obtain eight orientations so as to increase the quality of retrieved image. On the other hand, if no transformation is performed in order to speedup the encoder, the image quality will decay. In this paper, a direct allocating method to predict the desired transformation for similarity measure is proposed. Simulations show that the encoding time is almost the same as that of the method without transformations while the image quality is close to that of the standard method.

Two forms of vector modulation instability are observed in photonic crystal fiber. The strongly varying dispersion of these fibers result in complicated phasematching curves. We experimentally demonstrate the existence of broad regions of parametric gain.

A new approach is presented for analyzing the wall motion of cardiac left ventricle (LV) from 3D single photon emission computed tomography images. The technique applied in this paper is based on a statistical model which is one of special of physics-based deformable models. By means of content adaptive object model (CAOM) method, endocardial and epicardial surfaces of the LV can be obtained, thus a geometrical and grey-level model is built to represent wall motion by examining multi-phase cardiac images. Finally, the deformation and dynamic motion of the LV are estimated in terms of some parameters that vary during a heart cycle (about 700 ms). With the help of these parameters, physicians can characterize the motion of the LV in a clinically way and have a better treatment for possible diseases

We report on the observation of cross phase modulation instability (XPMI) in photonic crystal fiber (PCF). The rapidly varying dispersion of the fiber around its zero dispersion wavelength gives rise to a complicated phasematching curve.

Fabrication of a periodic plasma density structure in a gas jet with a boundary scale length approaching 10 μm was demonstrated. This technique has potential applications in various transient high-field plasma photonic devices. The capability of fabrication of gas/plasma density structures is the key to the development of plasma photonic devices such as plasma-based particle accelerators, x-ray lasers, high-harmonic generation, plasma nonlinear optics, etc. For instance, in the development of laser wakefield electron accelerator, it was proposed that by creating a sharp downward density ramp in the plasma, background electrons can be injected into the plasma wave at the ramp. In the development of high harmonic generation from gases, quasi-phase matching by using periodically interlaced layers of highand low-density gas or plasma was proposed to increase the conversion efficiency. The main obstacle for the realization of these ideas is that a gas/plasma density structure with a scale length of below 100 μm cannot be achieved by mechanical shaping of the gas jet nozzle, neither can a three-dimensional structure. In this work, we show that a density structure in a gas jet with a boundary scale length approaching 10 μm can be fabricated by direct optical machining. Although the desired structure only exists transiently (~10 ns), it is effectively static as far as the action of the photonic device is concerned (

We report on the observation of high energy ions with energies up to 1 MeV accelerated ponderomotively by a relativistically self-focused intense 5 TW, 400 fs laser pulse in a supersonic He gas jet on the distance of a laser spot size. Probing interferometry was used to observe on-axis electron-ion cavitation followed by the plasma expansion with a high radial velocity of /spl sim/3.8.10/sup 8/ cm/s. Using the nuclear track detector CR-39, we confirmed that the ions are preferentially accelerated in the radial direction and the total energy in high energy ions is about 1% of the laser energy. Developed kinetic modeling provides a reasonable description of a plasma channel formation and ion acceleration.

Accurate intra- and inter-patient quantitative analyses of the coronary vasculature will require accurate methods for determination of the 3D coronary tree as well as methods to relate these data to previously acquired vascular trees. The authors have developed methods for determination of the 3D coronary trees from biplane angiograms and for alignment of calculated 3D trees with previously acquired 2D projections. After alignment, the projected centerlines of the aligned 3D vasculature and those in the reference image were visually similar in shape and position. The variation in the average RMS difference between calculated and reference centerlines was 1.3 mm, indicating a high similarity between the shapes of the calculated and actual vessels. These results indicate that the 3D vascular structure reconstructed from two views is accurate and that previously calculated 3D trees can be aligned with previously acquired images.

We discuss the first experimental demonstration of electron acceleration by a laser wakefield over distances greater than a Rayleigh range (or the distance a laser normally propagates in vacuum). A self-modulated laser wakefield plasma wave is shown to have a field gradient that exceeds that of an RF linac by four orders of magnitude (E/spl ges/200 GV/m) and accelerates electrons with over 1-nC of charge per bunch in a beam with space-charge-limited emittance (1 mm-mrad). Above a laser power threshold, a plasma channel, created by the intense ultrashort laser pulse (I/spl sim/4/spl times/10/sup 18/ W/cm/sup 2/, /spl lambda/=1 /spl mu/m, /spl tau/=400 fs), was found to increase the laser propagation distance, decrease the electron beam divergence, and increase the electron energy. The plasma wave, directly measured with coherent Thomson scattering is shown to damp-due to beam loading-in a duration of 1.5 ps or /spl sim/100 plasma periods. We also discuss a new concept for controlled laser injection of electrons in order to create monoenergetic femtosecond electron bunches. As in the above experiments it uses the plasma itself as the cathode, but also an additional laser pulse as a trigger. By use of a 2-D particle-in-cell numerical code, it is shown that this technique will produce 1-femtosecond duration electron bunches with energy spread at the percent level.