High‑Performing Semiconductor Fibers Set a New Stage for Ambient Intelligence

An advance in the integration of high-performing semiconductors into fibers enables innovative fiber devices and fabric systems that sense,communicate and interact,paving the way for unprecedented applications in wearable technology,fabric computation,and ambient intelligence.

Quantum Boltzmann equation solved by Monte Carlo method for nano-scale semiconductor devices simulation

A two-dimensional （2D） full band self-consistent ensemble Monte Carlo （MC） method for solving the quantum Boltzmann equation, including collision broadening and quantum potential corrections, is developed to extend the MC method to the study of nano-scale semiconductor devices with obvious quantum mechanical （QM） effects. The quantum effects both in real space and momentum space in nano-scale semiconductor devices can be simulated. The effective mobility in the inversion layer of n and p channel MOSFET is simulated and compared with experimental data to verify this method. With this method 50nm ultra thin body silicon on insulator MOSFET are simulated. Results indicate that this method can be used to simulate the 2D QM effects in semiconductor devices including tunnelling effect.

A SPARSE MATRIX TECHNIQUE FOR SIMULATING SEMICONDUCTOR DEVICES AND ITS ALGORITHMS

A novel sparse matrix technique for the numerical analysis of semiconductor devicesand its algorithms are presented.Storage scheme and calculation procedure of the sparse matrixare described in detail.The sparse matrix technique in the device simulation can decrease storagegreatly with less CPU time and its implementation is very easy.Some algorithms and calculationexamples to show the time and space characteristics of the sparse matrix are given.

Recent developments in superjunction power devices

Superjunction(SJ)is one of the most innovative concepts in the field of power semiconductor devices and is often referred to as a"milestone"in power MOS.Its balanced charge field modulation mechanism breaks through the strong dependency between the doping concentration in the drift region and the breakdown voltage V_(B)in conventional devices.This results in a reduction of the trade-off relationship between specific on-resistance R_(on,sp)and V_(B)from the conventional R_(on,sp)∝V_(B)^(2.5)to R_(on,sp)∝W·V_(B)^(1.32),and even to R_(on,sp)∝W·V_(B)^(1.03).As the exponential term coefficient decreases,R_(on,sp)decreases with the cell width W,exhibiting a development pattern reminiscent of"Moore's Law".This paper provides an overview of the latest research developments in SJ power semiconductor devices.Firstly,it introduces the minimum specific on-resistance R_(on,min)theory of SJ devices,along with its combination with special effects like 3-D depletion and tunneling,discussing the development of R_(on,min)theory in the wide bandgap SJ field.Subsequently,it discusses the latest advancements in silicon-based and wide bandgap SJ power devices.Finally,it introduces the homogenization field(HOF)and high-K voltage-sustaining layers derived from the concept of SJ charge balance.SJ has made significant progress in device performance,reliability,and integration,and in the future,it will continue to evolve through deeper integration with different materials,processes,and packaging technologies,enhancing the overall performance of semiconductor power devices.

Advances in Rare Earth Application to Semiconductor Materials and Devices

The development of rare earths (RE) applications to semiconductor materials and devices is reviewed. The recent advances in RE doped silicon light emitting diodes (LED) and display materials are described. The various technologies of incorporating RE into semiconductor materials and devices are presented. The RE high dielectric materials, RE silicides and the phase transition of RE materials are also discussed. Finally, the paper describes the prospects of the RE application to semiconductor industry.

Identifying the enhancement mechanism of Al/MoO_(3) reactive multilayered films on the ignition ability of semiconductor bridge using a one-dimensional gas-solid two-phase flow model

Energetic Semiconductor bridge(ESCB)based on reactive multilayered films(RMFs)has a promising application in the miniature and intelligence of initiator and pyrotechnics device.Understanding the ignition enhancement mechanism of RMFs on semiconductor bridge(SCB)during the ignition process is crucial for the engineering and practical application of advanced initiator and pyrotechnics devices.In this study,a one-dimensional(1D)gas-solid two-phase flow ignition model was established to study the ignition process of ESCB to charge particles based on the reactivity of Al/MoO_(3) RMFs.In order to fully consider the coupled exothermic between the RMFs and the SCB plasma during the ignition process,the heat release of chemical reaction in RMFs was used as an internal heat source in this model.It is found that the exothermal reaction in RMFs improved the ignition performance of SCB.In the process of plasma rapid condensation with heat release,the product of RMFs enhanced the heat transfer process between the gas phase and the solid charge particle,which accelerated the expansion of hot plasma,and heated the solid charge particle as well as gas phase region with low temperature.In addition,it made up for pressure loss in the gas phase.During the plasma dissipation process,the exothermal chemical reaction in RMFs acted as the main heating source to heat the charge particle,making the surface temperature of the charge particle,gas pressure,and gas temperature rise continuously.This result may yield significant advantages in providing a universal ignition model for miniaturized ignition devices.

Progress in Antimonide Based III-V Compound Semiconductors and Devices

In recent years, the narrow bandgap antimonide based compound semiconductors (ABCS) are widely regarded as the first candidate materials for fabrication of the third generation infrared photon detectors and integrated circuits with ultra-high speed and ultra-low power consumption. Due to their unique bandgap structure and physical properties, it makes a vast space to develop various novel devices, and becomes a hot research area in many developed countries such as USA, Japan, Germany and Israel etc. Research progress in the preparation and application of ABCS materials, existing problems and some latest results are briefly introduced.

Overview of High Voltage SiC Power Semiconductor Devices: Development and Application

Research on high voltage(HV)silicon carbide(SiC)power semiconductor devices has attracted much attention in recent years.This paper overviews the development and status of HV SiC devices.Meanwhile,benefits of HV SiC devices are presented.The technologies and challenges for HV SiC device application in converter design are discussed.The state-of-the-art applications of HV SiC devices are also reviewed.

Effect of NO annealing on charge traps in oxide insulator and transition layer for 4H-SiC metal–oxide–semiconductor devices

The effect of nitric oxide（NO） annealing on charge traps in the oxide insulator and transition layer in n-type4H–Si C metal–oxide–semiconductor（MOS） devices has been investigated using the time-dependent bias stress（TDBS）,capacitance–voltage（C–V）,and secondary ion mass spectroscopy（SIMS）.It is revealed that two main categories of charge traps,near interface oxide traps（Nniot） and oxide traps（Not）,have different responses to the TDBS and C–V characteristics in NO-annealed and Ar-annealed samples.The Nniotare mainly responsible for the hysteresis occurring in the bidirectional C–V characteristics,which are very close to the semiconductor interface and can readily exchange charges with the inner semiconductor.However,Not is mainly responsible for the TDBS induced C–V shifts.Electrons tunneling into the Not are hardly released quickly when suffering TDBS,resulting in the problem of the threshold voltage stability.Compared with the Ar-annealed sample,Nniotcan be significantly suppressed by the NO annealing,but there is little improvement of Not.SIMS results demonstrate that the Nniotare distributed within the transition layer,which correlated with the existence of the excess silicon.During the NO annealing process,the excess Si atoms incorporate into nitrogen in the transition layer,allowing better relaxation of the interface strain and effectively reducing the width of the transition layer and the density of Nniot.

Preface to the Special Issue on Perovskite Semiconductor Optoelectronic Materials and Devices

Halide perovskite,a novel semiconductor material,was initially used in solar cells since 2009,and tremendous progresses have been witnessed in the last decade.The power conversion efficiency of the single perovskite solar cells has been incredibly increased up to 25.2%,and close to 30%efficiency was realized in perovskite/silicon tandem solar cells.Recently,the application of perovskite has been extended to the light-emitting diodes and photo-detectors.

Electroluminescent Excitation Mechanism of Erbium－activated Zinc Sulfide Semiconductor Thin Film Devices

The electroluminescunce (EL) transient characteristics of erbium-doped zinc sulfide thin film (TF) devices excited by short rectangular pulses are studied, the luminescence delay after de-exciting and the relaxation luminance peaks during decay are observed. A model description for energy transfer has been proposed. The experimental results can be theoretically explained with the computer curve fittings.

栅极几何结构对MIS栅结构常关p-GaN/AlGaN/GaN HEMTs性能的影响

高电子迁移率晶体管(high electron mobility transistors,HEMTs)具有高速开关和极高击穿电场等特性,在功率器件领域应用广泛。为提高HEMT器件性能,通过实验研究了栅极几何结构对具有金属/绝缘体/半导体(MIS)栅极结构的常关型p-GaN/AlGaN/GaN HEMTs性能的影响。栅极介质层采用5 nm厚的原位生长AlN,AlN/p-GaN界面呈现出更明显的能带弯曲和更宽的耗尽区,有利于阈值电压向正向偏移,且其相对较宽的能带错位有助于抑制栅极电流。实验结果表明:与栅极非覆盖区长度为0μm和6μm的MIS栅极相比,非覆盖区长度为3μm的MIS栅极可提高器件综合性能,有效抑制正向栅极电流,将阈值电压提高至3 V,并较好地保持电流密度为46 mA/mm;栅极结构中两侧没有栅极覆盖的区域在导通过程和导通状态下均可引起较大的沟道电阻,且沟道电阻随着非覆盖区长度增加而上升。

Direct Tunneling Effect in Metal-Semiconductor Contacts Simulated with Monte Carlo Method

Considering the tunneling effect and the Schottky effect,the metal semiconductor contact is simulated by using self consistent ensemble Monte Carlo method.Under different biases or at different barrier heights,the investigation into the tunneling current indicates that the tunneling effect is of great importance under reverse biases.The Schottky barrier diode current due to Schottky effect is in agreement with the theoretical one.The barrier lowering is found a profound effect on the current transport at the metal semiconductor interface.

Modeling analysis and optimization design of the thermostatical control system of laser instrument of the semiconductor

Influence produced by the heat effect at work of the laser instrument crystal of the semiconductor, the text designs a kind of temperature control system to the crystal of the laser instrument, using the thought and method of the classical control theory to analyze this temperature control system, and establishes mathematics model. According to mathematics model the text demonstrated the system at S field and time- area, and proposed optimizing basis to the total mark of proportion and differential parameter to con- troller PID, thus proposed a kind of temperature control scheme. And the thermostatically system is simulated by MATLAB.

High Performance 70nm CMOS Devices

A high performance 70nm CMOS device has been demonstrated for the first time in the continent, China. Some innovations in techniques are applied to restrain the short channel effect and improve the driving ability, such as 3nm nitrided oxide, dual poly Si gate electrode, novel super steep retrograde channel doping by heavy ion implantation, ultra shallow S/D extension formed by Ge PAI(Pre Amorphism Implantation) plus LEI(Low Energy Implantation), thin and low resistance Ti SALICIDE by Ge PAI and special cleaning, etc. The shortest channel length of the CMOS device is 70nm. The threshold voltages, G m and off current are 0 28V,490mS·mm -1 and 0 08nA/μm for NMOS and -0 3V,340mS·mm -1 and 0 2nA/μm for PMOS, respectively. Delays of 23 5ps/stage at 1 5V, 17 5ps/stage at 2 0V and 12 5ps/stage at 3V are achieved in the 57 stage unloaded 100nm CMOS ring oscillator circuits.

Temperature Dependence of Performance of 6H-SiC Unipolar Power Devices

The temperature dependence of some performance of 6H SiC unipolar power devices is analyzed theoretically.By employing the temperature dependent ionization coefficient and mobility of a silicon carbide,the analytical expressions of the temperature dependent performance,such as breakdown characteristics and on resistance of 6H SiC unipolar power devices are derived in a closed form.The analytical results are compared with the experimental results,with good accordance found in the breakdown characteristics.

一种新型可调驱动电压的SiC/Si混合开关驱动电路

为提高碳化硅金属氧化物半导体场效应晶体管(silicon carbide metal oxide semiconductor filed effect transistor,SiC-MOSFET)与硅基绝缘栅极双极晶体管(silicon insulated gate bipolar transistor,Si-IGBT)并联混合开关(SiC/Si hybrid switch,SiC/Si HyS)的可靠性与适用性,该文提出一种可变驱动电压的SiC/Si HyS栅极驱动电路结构,采用一路脉冲宽度调制(pulse width modulation,PWM)控制信号和一个驱动芯片产生不同电压幅值的栅极控制信号,分别控制SiC/Si HyS中的SiC-MOSFET和Si-IGBT。相比于传统采用2个独立驱动电路的SiC/Si HyS驱动结构,该驱动电路大幅度降低SiC/Si HyS栅极驱动电路的复杂度,降低SiC-MOSFET关断过程中Si-IGBT误导通的可能性,提升混合开关的工作可靠性。该文首先分析所设计驱动电路工作原理,给出驱动电压调节方法;其次,建立耦合电容端电压纹波和系统启动时电容端电压暂态数学模型,通过仿真和实验验证模型准确性;搭建2 kW的SiC/Si混合开关Buck电路,验证该文所提混合开关驱动电路可行性,从SiC/Si HyS功率器件关断损耗、驱动电路功率损耗、成本以及体积4个方面分析所提驱动结构的优势。

Black phosphorus-based field effect transistor devices for Ag ions detection

Black phosphorus （BP）, an attractive two-dimensional （2D） semiconductor, is widely used in the fields of optoelec- tronic devices, biomedicine, and chemical sensing. Silver ion （Ag＋）, a commonly used additive in food industry, can sterilize and keep food fresh. But excessive intake of Ag＋ will harm human health. Therefore, high sensitive, fast and simple Ag＋ detection method is significant. Here, a high-performance BP field effect transistor （FET） sensor is fabricated for Ag＋ detection with high sensitivity, rapid detection speed, and wide detection concentration range. The detection limit for Ag＋ is 10 l0 mol/L. Testing time for each sample by this method is 60 s. Besides, the mechanism of BP-FET sensor for Ag＋ detection is investigated systematically. The simple BP-FET sensor may inspire some relevant research and potential applications, such as providing an effective method for the actual detection of Ag＋, especially in wimessed inspections field of food.

Progress of power field effect transistor based on ultra-wide bandgap Ga_2O_3 semiconductor material

As a promising ultra-wide bandgap semiconductor, gallium oxide(Ga_2O_3) has attracted increasing attention in recent years. The high theoretical breakdown electrical field(8 MV/cm), ultra-wide bandgap(～ 4.8 eV) and large Baliga's figure of merit(BFOM) of Ga_2O_3 make it a potential candidate material for next generation high-power electronics, including diode and field effect transistor(FET). In this paper, we introduce the basic physical properties of Ga_2O_3 single crystal, and review the recent research process of Ga_2O_3 based field effect transistors. Furthermore, various structures of FETs have been summarized and compared, and the potential of Ga_2O_3 is preliminary revealed. Finally, the prospect of the Ga_2O_3 based FET for power electronics application is analyzed.

FINITE DIFFERENCE FRACTIONAL STEP METHODS FOR THE TRANSIENT BEHAVIOR OF A SEMICONDUCTOR DEVICE

Characteristic finite difference fractional step schemes are put forward. The electric potential equation is described by a seven-point finite difference scheme, and the electron and hole concentration equations are treated by a kind of characteristic finite difference fractional step methods. The temperature equation is described by a fractional step method. Thick and thin grids are made use of to form a complete set. Piecewise threefold quadratic interpolation, symmetrical extension, calculus of variations, commutativity of operator product, decomposition of high order difference operators and prior estimates are also made use of. Optimal order estimates in l2 norm are derived to determine the error of the approximate solution. The well-known problem is thorongley and completely solred.