Fabrication of nano-floating gate memories through atomic layer deposition incorporated with chemically-synthesized ZnO-nanocrystals

Nano-floating gate memories made of Al₂O₃/ZnO/Al₂O₃ nanostructures were fabricated with chemically-driven ZnO nanocrystals embedded into high-k Al₂O₃ thin films prepared through atomic layer deposition. The memory characteristics were analyzed through high-frequency capacitance–voltage measurement and current–voltage characteristics, along with high-resolution images of the aforementioned structures. The dotted ZnO nanocrystals function as charge-trapping/detrapping centers, inducing a very large memory window of 5.34 V. The defective nature of ZnO was optimally adjusted into the energy-band diagrams in combination with the tunneling and control layers of the robust Al₂O₃ thin films. The measured memory characteristics exhibited superior retention features derived from the charge-trapping/detrapping behaviors.     

激光波门干扰下的电视跟踪算法研究

针对低能激光对电视制导跟踪波门实施视场内干扰时,传统的电视跟踪算法无法跟踪目标的问题,提出了一种基于结构相似度的粒子滤波相关跟踪算法。首先在粒子候选区域内进行直方图均衡化,提取出目标空间直方图,然后计算波门背景区域与目标的结构相似度,从图像质量上判断粒子滤波器的跟踪状态,建立抗干扰跟踪模式,跟踪目标。实验表明：该算法克...     

Development and characteristic analysis of a field-plated Al2O3/AlInN/GaN MOS–HEMT

We present an AlInN/AlN/GaN MOS–HEMT with a 3 nm ultra-thin atomic layer deposition (ALD) Al₂O₃ dielectric layer and a 0.3 μm field-plate (FP)-MOS--HEMT. Compared with a conventional AlInN/AlN/GaN HEMT (HEMT) with the same dimensions, a FP-MOS--HEMT with a 0.6 μm gate length exhibits an improved maximum drain current of 1141 mA/mm, an improved peak extrinsic transconductance of 325 mS/mm and effective suppression of gate leakage in both the reverse direction (by about one order of magnitude) and the forward direction (by more than two orders of magnitude). Moreover, the peak extrinsic transconductance of the FP-MOS--HEMT is slightly larger than that of the HEMT, indicating an exciting improvement of transconductance performance. The sharp transition from depletion to accumulation in the capacitance--voltage (C--V) curve of the FP-MOS--HEMT demonstrates a high-quality interface of Al₂O₃/AlInN. In addition, a large off-state breakdown voltage of 133 V, a high field-plate efficiency of 170 V/μ m and a negligible double-pulse current collapse is achieved in the FP-MOS--HEMT. This is attributed to the adoption of an ultra-thin Al₂O₃ gate dielectric and also of a field-plate on the dielectric of an appropriate thickness. The results show a great potential application of the ultra-thin ALD-Al₂O₃ FP-MOS--HEMT to deliver high currents and power densities in high power microwave technologies.     

The electrical characteristics of a 4H-silicon carbide metal-insulator-semiconductor structure with Al2O3 as the gate dielectric

A 4H-silicon carbide metal-insulator-semiconductor structure with ultra-thin Al₂O₃ as the gate dielectric, deposited by atomic layer deposition on the epitaxial layer of a 4H-SiC (0001) 8⁰N-/N+ substrate, has been fabricated. The experimental results indicate that the prepared ultra-thin Al₂O₃ gate dielectric exhibits good physical and electrical characteristics, including a high breakdown electrical field of 25 MV/cm, excellent interface properties (1×10¹⁴ cm^-2) and low gate-leakage current (I_G = 1 × 10^-3 A/cm^-2@E_ox = 8 MV/cm). Analysis of the current conduction mechanism on the deposited Al₂O₃ gate dielectric was also systematically performed. The confirmed conduction mechanisms consisted of Fowler-Nordheim (FN) tunneling, the Frenkel-Poole mechanism, direct tunneling and Schottky emission, and the dominant current conduction mechanism depends on the applied electrical field. When the gate leakage current mechanism is dominated by FN tunneling, the barrier height of SiC/Al₂O₃ is 1.4 eV, which can meet the requirements of silicon carbide metal-insulator-semiconductor transistor devices.     

单轴应变硅nMOSFET栅隧穿电流模型

本文基于量子机制建立了单轴应变硅nMOSFET栅隧穿电流模型,分析了隧穿电流与器件结构参数、偏置电压及应力的关系.仿真分析结果与单轴应变硅nMOSFET的实验结果符合较好,表明该模型可行.同时与具有相同条件的双轴应变硅nMOSFET的实验结果相比,隧穿电流更小,从而表明单轴应变硅器件更具有优势.该模型物理机理明确,不仅适用于单轴应变硅nMOSFET,只要将相关的参数置换,该模型也同样适用于单轴应变硅pMOSFETs. 关键词： 单轴应变 nMOSFET 栅隧穿电流 模型     

Quantum SWAP gate with atomic ensembles in two distant cavities

A scheme is presented to realize remote quantum SWAP gate with atomic ensembles. During the process, the fiber mode is only virtually excited. The quantum information is encoded in two degenerate ground states, so the atoms' spontaneous emission can be omitted approximately. Moreover, the time needed to complete the gate is proportional to the inverse of the number of atoms and thus the gate is greatly speeded up as the number of atoms increases.     

Application of Polyvinyl Alcohol (PVA)/Carboxymethyl Cellulose (CMC) Hydrogel Produced by Conventional Crosslinking or by Freezing and Thawing

Hydrogels for this study were prepared from a mixture of PVA and CMC using three different techniques, i.e., freezing and thawing, electron‐beam irradiation or combined freezing and thawing and electron beam irradiation. A comparative study between the three techniques was carried out in terms of gel fraction (%) and swelling (%). It was found that the physical properties of the hydrogel were improved when the combination of freezing and thawing and irradiation were used rather than just freezing and thawing, or irradiation only. The effects of temperature and soil fertilizers on swelling (%) were examined to evaluate the usefulness of the hydrogel as a super absorbent in the soil. It was found that the swelling ratio increased as the composition of CMC increased in the blend. Hence, the blend having the composition 80/20 (CMC/PVA) was used as a super absorbent in the soil for agriculture. Moreover, the water retention increased in the soil containing this hydrogel. Thus, this type of hydrogel can be used to increase water retention in desert regions.     

Molecular Switches and Multiple Logic Gates Based on 4-(2-Pyridylazo)resorcinol

A simple‐structured 4‐(2‐pyridylazo)resorcinol (PAR) system presents interesting properties with dual fluorescent outputs. Modulated by solution pH two kinds of reversible switch behaviors, "ON‐OFF" and "OFF‐ON", were realized with the PAR system. Stimulated by different combination of external stimulus, such as metal ions, UV irradiation and solution pH, the PAR system could perform multiple logic functions including three inputs AND, two inputs INHIBIT and combinatorial "NOR/AND" in parallel. The operation of the designed system is very simple and detected with a high sensitive fluorescent signal.     

Protected two-qubit entangling gate with mechanical driven continuous dynamical decoupling

In this work, we propose a high-fidelity phonon-mediated entangling gate in a hybrid mechanical system based on two silicon-vacancy color centers in diamond. In order to suppress the influence of the spin decoherence on the entangling gate, we use a continuous dynamical decoupling approach to create new dressed spin states, which are less sensitive to environmental fluctuations and exhibit an extended ${T}_{2}^{* }$ spin dephasing time. The effective spin–spin Hamiltonian modified by the mechanical driving field and the corresponding master equation are derived in the dispersive regime. We show that in the presence of the mechanical driving field, the effective spin–spin coupling can be highly controlled. By calculating the entangling gate fidelity in the dressed basis, we find that once the mechanical field is turned on, the gate fidelity can be significantly improved. In particular, under an optimized spin-phonon detuning and a stronger Rabi frequency of the mechanical driving field, the two-qubit gate is capable of reaching fidelity exceeding 0.99. Moreover, by employing appropriate driving modulation, we show that a high-fidelity full quantum gate can be also realized, in which the initial and final spin states are on a bare basis. Our work provides a promising scheme for realizing high-fidelity quantum information processing.