终端场板结构对GaN基肖特基势垒二极管击穿电压的影响

为了提高肖特基势垒二极管(Schottky barrier diode,SBD)的击穿电压(breakdown voltage,BV),系统研究了终端场板结构的GaN-SBD.基于Silvaco TCAD软件,采用控制变量法即分别在不同场板长度(LFP)和绝缘层厚度(TFP)及GaN漂移区掺杂浓度(ND)条件下仿真了器...     

p型栅结构氮化镓基高电子迁移率晶体管结构优化

为了简化后期栅极驱动电路设计、降低成本,工业界对增强型高电子迁移率晶体管的需求与日俱增.采用p型栅结构制备增强型器件的方法是目前极有前景的一种增强型方法.该方法致力于提高器件的正向阈值电压和输出饱和电流,通过Silvaco TCAD软件调节AlGaN势垒层厚度及其Al组分,仿真器件转移特性曲线和输出特性曲线.将AlGa...     

硅肖特基结自滤波窄带近红外光探测器的研究

窄带近红外光探测器因对特定波长有很高的灵敏度,在临床诊断、治疗设备或可穿戴的功能性监测设备等生物医学领域具有广阔的应用前景.文章基于硅基光吸收及肖特基结光生载流子收集特性的分析,首次采用Silvaco TCAD设计了光谱可调的硅/石墨烯肖特基二极管窄带近红外光探测器.利用湿法转移石墨烯电极制备了硅/石墨烯肖特基二极管,...     

实验设计与模拟相结合用于IC优化设计的TCAD工具

鉴于PC机广泛普及和使用方便,在PC机上建立起实验设计与模拟相结合用于IC优化设计的TCAD工具。利用已有的工艺模拟软件SUPREM、器件模拟软件MINIMOS及电路模拟软件PSPICE,完成了响应表面拟合、SPICE模型参数提取及数据转换等程序,形成一个可以进行工艺、器件及电路分析和优化设计的TCAD工具,并用于研究实验设计方法在IC优化设计中的应用。     

一种带有浮空阶梯场板的AlGaN/GaN SBD仿真

研究了一种带有浮空阶梯场板的AlGaN/GaN肖特基势垒二极管结构—SFFP-SBD(Stepped Insulator Floating Field Plate).该结构是结合浮空场板,阶梯场板的优点,在反向状态下,浮空阶梯场板和横向场板之间的静电荷影响沟道内的电场,在沟道内形成电场峰值,并且浮空阶梯场的钝化层较厚,场板向阴极方向延伸,浮空阶梯场板的调制沟道作用会更加明显,提升反向耐压效果明显.使用Silvaco TCAD软件对器件的浮空阶梯场板的钝化层厚度和水平位置进行优化,仿真结果显示,钝化层厚度为500 nm,S为0μm时,击穿电压达到最大为-900 V.因此,该器件可以应用在高电压的电路中.     

基于TCAD的门极换流晶闸管的研究

文章基于ISE公司的半导体仿真软件TCAD系列软件对GCT进行了模拟,通过建立的GCT模型,研究了透明阳极结构和栅极数目对通态特性的影响。模拟结果表明,透明阳极中的杂质总量是决定GCT的通态压降的关键因素,杂质总量越多,通态压降越低。研究成果对GCT器件的设计和制造具有重要的参考价值。     

Copper nanoclusters: Synthesis,characterization and properties

Metal nanoclusters with a core size smaller than 2 nm have attracted much attention because of their unique physical and chemical properties.Among the studied metal nanoclusters,gold and silver have been studied extensively by size-controlled synthesis, structural characterization and properties investigations.Recently,considerable research effort has been devoted to the investiga- tion of copper nanoclusters.In this review,we highlight recent progress in the study of copper nanoclusters in terms of synthesis methods,characterization techniques and their novel optical and catalytic properties.     

Probing the properties of individual nanostructures by novel techniques

Nanomaterials are the fundamental components of nanoscience and nanotechnology, and they are different from bulk materials in grain size, surface/interface-to-volume ratio and grain shape, which are the origins of their unique electrical, optical, thermodynamic, mechanical and chemical properties. The small size of nanostructures hampers the applications of well-established testing and measurement techniques, thus new methods and approaches must be developed for their synthesis, property characterization and device fabrication. This has been the focus of our research, aiming at exploring state-of-the-art techniques for materials processing and characterization. This paper reviews our progress in nanomaterials research.     

A Characterization of the Polarity Mapping for Convex Bodies

In this paper, we establish a characterization of the polarity mapping for convex bodies for 1-dimensional convex bodies, which is a supplement to the result for such a characterization obtained by B?r?czky and Schneider.     

Morphology and microstructure characterization of 95W-3.5Ni-1.5Fe powder prepared by mechanical alloying

Morphology and microstructure characterization of 95W-3.5Ni-1.5Fe powder prepared by mechanical alloying@Islam S.Humail$State Key Laboratory for Advanced Metals and Materials,Materials Science and Engineering School, University of Science and Technology B…     

Characterization of Pentachlorophenol in Soil by Liquid Chromatography-Mass Spectrometry

A simple, accurate and sensitive method for characterization of pentachlorophenol in soil was presented. The method included Soxhlet extraction using extracting agent of methanol/water/triethylamine (80∶20∶2), decontamination using solid-phase extraction (SPE) column and characterization by liquid chromatography-mass spectrometry (LCMS). The developed analytical method was successfully used to the determination of pentachlorophenol in soil samples.     

半导体器件模拟软件ISE—TCAD

本文的研究目的是对半导体模拟软件ISE—TCAD进行详细介绍,旨在介绍软件的模拟方法,并利用仿真软件ISE—TCAD对其在室温下的正向伏安特性与反向伏安特性进行了模拟仿真,并取得了有价值的数据．．从模拟图的结果可知室温（303K）且偏压较低时,电流随着电压呈指数关系增长。W／SiC肖特基势垒二极管的开启电压约为0．2V;偏压较高时,电流增加缓慢,串联电阻效应明显。模拟值表明反向电流数值比正向数值小几个数量级,     

Physicochemical characterization of Baizhi particles by ultrafine pulverization

Baizhi, as a medicinal plant, has been demonstrated to be useful for the treatment of aches and pains in China. The physicochemical characterization of Baizhi particles is greatly influenced by ultrafine pulverization. To study the physicochemical characterization of Baizhi, the raw plant material of Baizhi was ground to 6 μm particles by a high speed centrifugal sheering (HSCS) pulverizer. The micron particles were characterized by optical microscopy and scanning electron microscopy (SEM). Imperatorin is one of the active ingredients of Baizhi, and its extraction yield is determined to evaluate the chemical characterization of Baizhi powder. Imperatorin was analyzed by high performance liquid chromatography (HPLC). The results show that after ultrafine pulverization, the plant cell walls are broken into pieces and the extraction yield of imperatorin is increased by 11.93% compared with the normal particles.     

Dog Bone栅型MOS场效应晶体管的等效宽长比计算

Dog Bone栅型MOS场效应晶体管是一种对称性的、防辐射总剂量效应的版图结构。为了计算其等效宽长比,把它划分为常规结构的主MOS晶体管和非常规结构的边缘MOS晶体管2种类型的并联。借助Silvaco TCAD工艺与器件仿真工具构建了它的模型,分析了主MOS晶体管的宽度、长度和边缘MOS晶体管的多晶硅与有源区的交叠宽度对边缘MOS等效宽长比的影响,得到拟合的Dog Bone栅型MOS晶体管等效宽长比的计算公式。采用CSMC 0.5μm DPTMCMOS混合信号工艺制作了样管,对实验测量值和公式计算值进行比较,Dog Bone栅型MOS场效应晶体管的等效宽长比的计算公式与实验能够较好地吻合。     

局部可积微分系统和它们的正规型

In this paper we first summarize our results published in recent years and their sketch proofs on local integrability,which are on the characterization of local integrability and on the existence of analytic normalization of analytically integrable differential systems. Then we present a new result on the equivalent characterization of the existence of the first integrals of an analytic differential systems near a nonhyperbolic singularity. Finally we pose some open problems on this subject.     

New insights into the properties of high-manganese steel

In the Collaborative Research Centre 761’s“Steel ab initio-quantum mechanics guided design of new Fe based materials,”scientists and engineers from RWTH Aachen University and the Max Planck Institute for Iron Research conducted research on mechanism-controlled material development with a particular focus on high-manganese alloyed steels.From 2007 to 2019,a total of 55 partial projects and four transfer projects with industrial participation(some running until 2021)have studied material and process design as well as material characterization.The basic idea of the Collaborative Research Centre was to develop a new methodological approach to the design of structural materials.This paper focuses on selected results with respect to the mechanical properties of high-manganese steels,their underlying physical phenomena,and the specific characterization and modeling tools used for this new class of materials.These steels have microstructures that require characterization by the use of modern methods at the nm-scale.Along the process routes,the generation of segregations must be taken into account.Finally,the mechanical properties show a characteristic temperature dependence and peculiarities in their fracture behavior.The mechanical properties and especially bake hardening are affected by short-range ordering phenomena.The strain hardening can be adjusted in a never-before-possible range,which makes these steels attractive for demanding sheet-steel applications.     

具有一个Lindelf因子的积的正规性(英文)

In this paper a characterization theorem of the normality of products witha Lindel(?)f factor will be proved.The theorem as well as the well known Przym-usinski′s and Rudin′s characterization theorems of the normality of products wi-th a compact factor is a corollary of Theorem 1 below.Throughout this paper we assume that all spaces are T_1.The letterωdenotesthe first infinite cardinal;κ,λdenote the cardinal numbers and other Greek le-     

Comparative Study of Reverse Algorithms via Artificial Neural Networks Based on Simulated Indentation Tests

The advances in the instrumented indentation equipments and the need to assess the properties of materials of small volume such as those constitute the micro-electro-mechanical devices, micro-electronic packages, and thin films have propelled the interest in material characterization via indentation tests. The load-displacement curves and their characteristics, namely, the curvature of the loading path, C, and the ratio of the remaining and total work done, WR / WT, can be conveniently obtained from finite element simulations for various elasto-plastic material properties. The paper reports the comparative study on two reverse neural networks algorithms involving several combinations of databases established from the results obtained from simulated indentation tests. The performance of each set of results is analyzed and the most appropriate algorithm identified and reported. The approach with the selected neural networks model has great potential in practical applications on the characterization of a small volume of materials.     

Characterizations of L_p(R) Using Tight Wavelet Frames

In this paper,a Littlewood-Paley function characterization of the spaces L p(R),1p∞,is first established by means of the equivalent conditions of tight wavelet frames,wherein the Littlewood-Paley function is associated with a tight wavelet frame generated by the so-called extension principles.With the above characterization,another characterization of L p(R),1p∞,is also established in terms of the weighted l 2-norm of the wavelet frame coefficients,which can be a useful tool in harmonic analysis,approximation theory,and image processing.     

利用TCAD方法优化设计金属栅CMOS工艺及电路

为了降低集成电路制造工艺的成本,用计算机辅助工艺设计(TCAD)的方法开发了金属铝栅CMOS工艺.首先利用3μm金属铝栅工艺对模拟软件TSUPREM-4和器件模拟软件MED ICI进行了校准,再对金属铝栅1.5μm短沟道CMOS工艺进行器件结构、工艺和电气性能等参数的模拟,以最简约工艺在现有工艺线上成功流水了1.5μm铝栅CMOS.实际测试阈值电压为±0.6V,击穿达到11V,各项指标参数的模拟与实际测试误差在5%以内,并将工艺开发和电路设计结合起来,用电路的性能验证了工艺.利用TCAD方法已成为集成电路和分立器件设计和制造的重要方法.