High-precision X-ray characterization for basic materials in modern high-end integrated circuit

Semiconductor materials exemplify humanity's unwavering pursuit of enhanced performance,efficiency,and functionality in electronic devices.From its early iterations to the advanced variants of today,this field has undergone an extraordinary evolution.As the reliability requirements of integrated circuits continue to increase,the industry is placing greater emphasis on the crystal qualities.Consequently,conducting a range of characterization tests on the crystals has become necessary.This paper will examine the correlation between crystal quality,device performance,and production yield,emphasizing the significance of crystal characterization tests and the important role of high-precision synchrotron radiation X-ray topography characterization in semiconductor analysis.Finally,we will cover the specific applications of synchrotron radiation characterization in the development of semiconductor materials.

p‑Type Two‑Dimensional Semiconductors:From Materials Preparation to Electronic Applications

Two-dimensional(2D)materials are regarded as promising candidates in many applications,including electronics and optoelectronics,because of their superior properties,including atomic-level thickness,tunable bandgaps,large specific surface area,and high carrier mobility.In order to bring 2D materials from the laboratory to industrialized applications,materials preparation is the first prerequisite.Compared to the n-type analogs,the family of p-type 2D semiconductors is relatively small,which limits the broad integration of 2D semiconductors in practical applications such as complementary logic circuits.So far,many efforts have been made in the preparation of p-type 2D semiconductors.In this review,we overview recent progresses achieved in the preparation of p-type 2D semiconductors and highlight some promising methods to realize their controllable preparation by following both the top-down and bottom-up strategies.Then,we summarize some significant application of p-type 2D semiconductors in electronic and optoelectronic devices and their superiorities.In end,we conclude the challenges existed in this field and propose the potential opportunities in aspects from the discovery of novel p-type 2D semiconductors,their controlled mass preparation,compatible engineering with silicon production line,high-κdielectric materials,to integration and applications of p-type 2D semiconductors and their heterostructures in electronic and optoelectronic devices.Overall,we believe that this review will guide the design of preparation systems to fulfill the controllable growth of p-type 2D semiconductors with high quality and thus lay the foundations for their potential application in electronics and optoelectronics.

Thermodynamic analysis of growth of ternary Ⅲ-Ⅴ semiconductor materials by molecular-beam epitaxy

Thermodynamic models for molecular-beam epitaxy（MBE） growth of ternary Ⅲ-Ⅴ semiconductor materials are proposed.These models are in agreement with our experimental materials InGaP/GaAs and InGaAs/InP,and reported GaAsP/GaAs and InAsP/InP in thermodynamic growth.The lattice strain energy △G and thermal decomposition sensitive to growth temperature are demonstrated in the models simultaneously.△G is the function of the alloy composition,which is affected by flux ratio and growth temperature directly.The calculation results reveal that flux ratio and growth temperature mainly influence the growth process.Thermodynamic model of quaternary InGaAsP/GaAs semiconductor material is discussed also.

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.

In-situ monitoring of dynamic behavior of catalyst materials and reaction intermediates in semiconductor catalytic processes

Semiconductor photocatalysis, as a key part of solar energy utilization, has far-reaching implications for industrial, agricultural, and commercial development. Lack of understanding of the catalyst evolution and the reaction mechanism is a critical obstacle for designing efficient and stable photocatalysts. This review summarizes the recent progress of in-situ exploring the dynamic behavior of catalyst materials and reaction intermediates. Semiconductor photocatalytic processes and two major classes of in-situ techniques that include microscopic imaging and spectroscopic characterization are presented. Finally, problems and challenges in in-situ characterization are proposed, geared toward developing more advanced in-situ techniques and monitoring more accurate and realistic reaction processes, to guide designing advanced photocatalysts.

STUDY ON THE STRUCTURE AND PROPERTIES OF SEMICONDUCTOR CERAMIC COOLING MATERIALS

In this paper, thermoelectric polycrystal ceramic materials were prepared by a new ceramic technology. The p-type 72% Sb2Te3+ 25%Bi2Te3 + 3%Sb2Se3 doped with Te and 90%Bi2Te3 + 5%Sb2Te3 + 5%Sb2Se3 doped with SbI3 or AgI samples were studied. The new ceramic cooling materials have an inhomo-geneous structure, higher mechanical strength and the thermoelectric properties. With the help of phase diagrams, Differantial Thermal Analysis, X-Ray diffractograms, the observation of high temperature microscope and the relation between technology conditions and thermoelectric properties were obtained in optimum technology conditions. Measurements of properties show that the sintering temperature and time have an effect on the thermoelectric properties of the samples. Scan electronic microscope shows that the polycrystal ceramic materical has an obvious layered structure. Electrical probe microscope analysis indicates that the mol contents of Bi, Te,Sb and Se which compose samples are re- spectively comsistent with original compositions. The distribution of these elements in the samples is well uniform. Doping materials has been studied including doping variety and doping concentration. The figure of merit of n-type doped SbI3 is 2.9 × 10-3 1/k. The figure of merit of p-type doped Te is 3. 1 ×10-3 1/ K.

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.

Preparation of Single Crystals of Co_xZn_(1-x)S and Co_xZn_(1-x)Se—New Materials of Dilute Magnetic Semiconductors

In this paper, we report the growth of single crystals of Co_x Zn_(1-x)S and Co_x Zn_(1-x)Se (0<x<0.3) by the method of chemical transport, using iodine as a transport agent. The light green color of single crystal Co_xZn_(1-x)S as well as the light brown color of Co_xZn_(1-x)Se become deep with an increase in x. The compositions of the single crystals were nearly stoichiometric. The transfer rate decreases with an increase of the x value. The growth rate was related to the temperature difference. The large temperature difference speed up the growth rate, but the size of crystal obtained was small. In general, the optimal temperature difference was 15℃. From X-ray diffraction measurements, the structures of crystals Co_xZn_(1-x)S and Co_xZn_(1-x)Se (0<x<0.1) were identified to be zinc blende structure similar to that of ZnS and ZnSe.

Developing Suitable Sensitive Compound Semiconductor Materials Doped by Transition Metals for Occupational Thermoluminescence Dosimetry

The essential objective of radiation dosimetry is to develop suitable sensitive materials for different measurements in radiation fields. Our exploration is to find potentially suitable high gamma radiation dosimeters in the range from 0.5E4 to 1.5E4 Gy. Gamma rays source (60Co, 136 Gy/min) has been used. Many compound semiconductor materials were prepared and investigated. Thermoluminescence (TL) glow curve was analyzed into its component by analytical segregation program using computerized glow curve deconvolution (CGCD). Three zero dose readings for non-irradiated powders of the materials have been taken as lower limit of detection. The results indicated that some of the tested materials have exhibited TL linearly with respect to dose. In addition, dose response of these materials was found to be useful for high radiation dosimetry. Glow curve structures exhibited several peaks corresponding to the various energies of the emptied traps. Variation in the standard deviation for reusability cycles has been ten readout. The fading at ambient temperature was studied up to 60 days which reached a relative stability (~1.5% for all), 10 days after irradiation. A typical glow curve of CoPa which irradiated with 1.5E4 Gy was analyzed. Characterizations of tested materials indicated that crystals of ZnLa:Li, ZnLa:Cd, and ZnLa:Cr have stable and increasing thermoluminescent responses with high gamma radiation dose range. Special glow peaks can be used as estimators for absorbed doses as well as re-estimation for time elapsed exposures.

Electronic structure engineering in organic thermoelectric materials

Electronic structures, which play a key role in determining electrical and optical properties of π-conjugated organic materials, have attracted tremendous interest. Efficient thermoelectric (TE) conversion of organic materials has rigorous requirements on electronic structures. Recently, the rational design and precise modulation of electronic structures have exhibited great potential in exploring state-of-the-art organic TE materials. This review focuses on the regulation of electronic structures of organic materials toward efficient TE conversion. First, we present the basic knowledge regarding electronic structures and the requirements for efficient TE conversion of organic materials, followed by a brief introduction of commonly used methods for electronic structure characterization. Next, we highlight the key strategies of electronic structure engineering for high-performance organic TE materials. Finally, an overview of the electronic structure engineering of organic TE materials, along with current challenges and future research directions, are provided.

Review on Recent Progress of Nanostructured Anode Materials for Li-Ion Batteries

Lithium ion battery (LIB) is one of the promising power storage devices in today’s world. Lithium ion battery like other types of electrochemical cell has anodic and cathodic electrode in which lithium ion is intercalated and deinterclated during charging and discharging process respectively. The capacity of lithium ion battery is improved by the development of innovative kinds of electrode. Carbon, metal/semiconductor, metal oxides and metal phosphides/ nitrides/sulfides based nanomaterials improve the capability of LIBs due to their high surface area, low diffusion distance, high electrical and ionic conductivity. Nanostructured materials represent a rapidly growing area in the field of Li-ion batteries because of their substantial advantages in terms of mass transport. In this review anode nanomaterials classified based on type of transition metal/semiconductor such as carbon, silicon, titanium and tin based nanomaterials are discussed. Additionally, different electrochemical reactions, comparative influence of anode materials on LIBs and their applications are widely explained.

Materials Studio辅助半导体物理学教学改革与实践

半导体物理学是物理电子类专业最重要的专业课之一,对其学习掌握的成效直接影响学生综合素质的培养。现如今,半导体学科的飞速发展对半导体物理学课程教学提出了新的高要求,其相应的教学模式必须与时俱进。针对许多高校目前存在的实验条件不足、相关设备配置不齐等情况,文章利用材料计算软件搭建虚拟半导体学习平台,以弥补传统多媒体教学手段在相关学习过程中的诸多不足。实践证明,这一方式能够十分有效地激发学生学习的热情,显著改善教学质量。文章着重介绍了半导体物理学教学的特点及现状,随后利用Materials Studio软件实际展示了新教学模式下提高教学质量的方法。

A Novel Semiconductor CIGS Photovoltaic Material and Thin-Film ED Technology

In order to achieve low cost high efficiency thin film solar cells,a novel Semiconductor Photovoltaic (PV) active material CuIn 1-x Ga x Se 2 (CIGS) and thin film Electro Deposition (ED) technology is explored.Firstly,the PV materials and technologies is investigated,then the detailed experimental processes of CIGS/Mo/glass structure by using the novel ED technology and the results are reported.These results shows that high quality CIGS polycrystalline thin films can be obtained by the ED method,in which the polycrystalline CIGS is definitely identified by the (112),(204,220) characteristic peaks of the tetragonal structure,the continuous CIGS thin film layers with particle average size of about 2μm of length and around 1 6μm of thickness.The thickness and solar grade quality of CIGS thin films can be produced with good repeatability.Discussion and analysis on the ED technique,CIGS energy band and sodium (Na) impurity properties,were also performed.The alloy CIGS exhibits not only increasing band gap with increasing x ,but also a change in material properties that is relevant to the device operation.The beneficial impurity Na originating from the low cost soda lime glass substrate becomes one prerequisite for high quality CIGS films.These novel material and technology are very useful for low cost high efficiency thin film solar cells and other devices.

Raman Scattering Spectrum Analysis of GaP andIts Luminous Materialsr

Abstract: The Raman scattering spectra of n- type GaP(doped S) single crystal and red and green luminous materials grown on the n - type GaP (doped S) single crys-tal substrate by liquid - phase epitaxy are analyed. The results show that the spectra of GaP single crystal and its luminous materials include not only the first - order longitudi-nal optical photons and transverse optical phonons Raman scattering peaks, but also the peaks of the bound excitons, bound electrons and bound holes.

Drain-induced barrier lowering effect for short channel dual material gate 4H silicon carbide metal-semiconductor field-effect transistor

Sub-threshold characteristics of the dual material gate 4H-SiC MESFET （DMGFET） are investigated and the analytical models to describe the drain-induced barrier lowering （DIBL） effect are derived by solving one- and two- dimensional Poisson＇s equations. Using these models, we calculate the bottom potential of the channel and the threshold voltage shift, which characterize the drain-induced barrier lowering （DIBL） effect. The calculated results reveal that the dual material gate （DMG） structure alleviates the deterioration of the threshold voltage and thus suppresses the DIBL effect due to the introduced step function, which originates from the work function difference of the two gate materials when compared with the conventional single material gate metal-semiconductor field-effect transistor （SMGFET）.

Recent progress on ambipolar 2D semiconductors in emergent reconfigurable electronics and optoelectronics

In these days,the increasing massive data are being produced and demanded to be processed with the rapid growth of information technology.It is difficult to rely solely on the shrinking of semiconductor devices and scale-up of the integrated circuits(ICs)again in the foreseeable future.Exploring new materials,new-principle semiconductor devices and new computing architectures is becoming an urgent topic in this field.Ambipolar two-dimensional(2D)semiconductors,possessing excellent electrostatic field controllability and flexibly modulated major charge carriers,offer a possibility to construct reconfigurable devices and enable the ICs with new functions,showing great potential in computing capacity,energy efficiency,time delay and cost.This review focuses on the recent significant advancements in reconfigurable electronic and optoelectronic devices of ambipolar 2D semiconductors,and demonstrates their potential approach towards ICs,like reconfigurable circuits and neuromorphic chips.It is expected to help readers understand the device design principle of ambipolar 2D semiconductors,and push forward exploring more new-principle devices and new-architecture computing circuits,and even their product applications.

A family of flexible two-dimensional semiconductors:MgMX2Y6(M=Ti/Zr/Hf;X=Si/Ge;Y=S/Se/Te)

Inspired by the recently predicted 2D MX_(2)Y_(6)(M=metal element;X=Si/Ge/Sn;Y=S/Se/Te),we explore the possible applications of alkaline earth metal(using magnesium as example)in this family based on the idea of element replacement and valence electron balance.Herein,we report a new family of 2D quaternary compounds,namely MgMX_(2)Y_(6)(M=Ti/Zr/Hf;X=Si/Ge;Y=S/Se/Te)monolayers,with superior kinetic,thermodynamic and mechanical stability.In addition,our results indicate that MgMX_(2)Y_(6)monolayers are all indirect band gap semiconductors with band gap values ranging from 0.870 to 2.500 eV.Moreover,the band edges and optical properties of 2D MgMX_(2)Y_(6)are suitable for constructing multifunctional optoelectronic devices.Furthermore,for comparison,the mechanical,electronic and optical properties of In_(2)X_(2)Y_(6)monolayers have been discussed in detail.The success of introducing Mg into the 2D MX_(2)Y_(6)family indicates that more potential materials,such as Caand Sr-based 2D MX_(2)Y_(6)monolayers,may be discovered in the future.Therefore,this work not only broadens the existing family of 2D semiconductors,but it also provides beneficial results for the future.

脑神经血管功能体系及其评估方法的展望

人脑具有极为精妙的神经血管功能体系以满足脑细胞对能量代谢刻不容缓的需求。然而,现有的仪器设备仅能探测单一的神经血管功能,导致碎片化认知,许多与神经血管疾病相关的科学问题悬而未决。本文旨在回顾在面对重大疾病时脑血流自动调节功能、脑血管反应性功能、神经血管耦联功能以及自主神经功能等神经血管功能所扮演的角色,并探讨多功能、多范式、高分辨率的人体多模态跨尺度神经血管功能测量系统的可行性,为深入研究脑血管病及神经退行性疾病等重大神经血管疾病的新理论和新机制提供科学工具。

基于半导体桥和含能材料的信息储存介质自毁模块研究

针对高安全等级信息储存介质硬件层面的防护,开展了基于半导体桥(SCB)和含能材料的低驱动能量自毁模块的研究.建立了SCB等离子体发火、能量传递、含能材料点火的数学模型并完成了理论计算,利用COMSOL搭建SCB多物理场仿真模型并校核其性能,搭建了试验平台并进行SCB与含能材料发火性能测试的试验.仿真和试验结果表明:含能自毁模块具有优良的发火性能,能在5 V充电电压的激励下,起爆SCB桥区并使桥区温度能在18μs内达到2700 K,从而激发0.43 mg叠氮化铜在50μs内起爆产生爆轰波.含能自毁模块能够完成能量的传递并摧毁目标信息储存介质,有效避免信息储存介质关键信息被窃取,保证了信息储存介质的安全性.

基于稀疏成像的半导体薄膜材料界面缺陷检测

复杂背景下检测半导体薄膜材料界面微小缺陷具有一定的难度,为了精准检测半导体薄膜材料界面缺陷,提出一种稀疏成像下半导体薄膜材料界面缺陷检测方法。扫描采集半导体薄膜材料界面二维图像,对含有噪声的半导体薄膜材料界面实施小波分解,获取不同频带的子图像。低频图像保持不变,选择对应的模板对高频图像滤波处理,将滤波处理后的高频图像和低频图像两者合成,获取去噪后的图像。通过机器视觉定位薄膜材料界面的缺陷位置,提取缺陷区域特征,采用稀疏成像对特征参数修正,完成半导体薄膜材料界面缺陷检测。仿真结果表明,采用所提方法可以获取更加精准的检测结果,用时比较短,满足高效与高精度检测需求。