宽禁带与超宽禁带半导体器件新进展

 宽禁带、超宽禁带半导体器件已经成为国际半导体器件和材料的研究和产业化热点，概述了半导体材料的划代，综述了宽禁带、超宽禁带半导体器件和材料最新进展，并展望了未来的发展方向和前景。     

高灵敏度宽禁带半导体紫外探测器

以碳化硅(SiC)和Ⅲ族氮化物为代表的宽禁带半导体是近年来国内外重点研究和发展的新型第三代半导体材料,具有禁带宽度大、导热性能好、电子饱和漂移速度高以及化学稳定性优等特点,用于工作于紫外波段的光探测器件具有显著的材料性能优势.宽禁带半导体紫外探测器的主要应用包括:国防预警、环境监测、化工和生化反应的光谱分析和过程检测、以及天文研究等.本文主要回顾近年来南京大学在此方面开展的一些代表工作,所涉及到的典型器件有:具有极低暗电流的AlGaN基日盲MSM紫外探测器、高量子效率AlGaN基日盲雪崩光电探测器、以及SiC基可见光盲紫外单光子探测器.     

第三代宽禁带功率半导体及应用发展现状

 近年来，以碳化硅和氮化镓为代表的第三代宽禁带功率半导体迅猛发展，已成为中国功率电子行业的研发和产业化应用的重点。抓住第三代宽禁带功率半导体的战略机遇期，实现半导体材料、器件、封装模块和系统开发的自主可控，对保障工业创新体系的可持续发展至关重要。在分析第三代宽禁带功率半导体重要战略意义的基础上，综述了其材料、器件研发和产业的发展现状，阐述了碳化硅及氮化镓器件在当前环境下的应用成果，剖析了第三代半导体行业存在的关键问题。建议在国家政策的进一步领导之下，发挥行业协会和产业联盟的桥梁和纽带作用，对衬底材料、外延材料、芯片与器件设计和制造工艺等产业链各环节进行整体支撑，引导各环节间实现资源共享、强强联合，上下游互相拉动和促进，形成一个布局合理、结构完整的产业链。     

《半导体器件》课程中GaN基光电器件差异性教学探讨

在《半导体器件》课程中加强宽禁带半导体器件的教学是科学技术与国民经济快速发展对高等学校基本职能所提出的根本要求。本文阐述了把第三代宽禁带半导体GaN基光电器件作为新型半导体器件进行重点教学的必要性和意义．同时也指出需要采用差异化的教学方法来讲授新型器件在结构、工作原理与光电性能等方面的特殊表现。     

广东省第三代半导体创新发展刍议

第三代半导体是指以氮化镓(GaN)、碳化硅(SiC)为代表的宽禁带半导体(禁带宽度大于2 eV),近年来扩展至氮化铝(AlN)、金刚石、氧化镓(Ga2O3)、氮化硼(BN)等超宽禁带半导体.相比于以硅(Si)、锗(Ge)为代表的第一代半导体和以砷化镓(GaAs)、磷化铟(InP)为代表的第二代半导体,第三代半导体具有更...     

宽禁带半导体 中国科学家谈科学

宽禁带半导体,突破了第一、二代半导体材料的居里温度远低于室温的困境,在高温、大功率应用中有很大的潜力。在同一材料体系实现非易失性自旋存储和电、光信号处理器件的集成,将成为宽禁带半导体微电子发展的远期目标。     

天域半导体:聚焦核心技术攻关推动碳化硅半导体产业发展

第三代半导体碳化硅(SiC)作为典型的宽禁带半导体材料,因其优越的物理特性,非常适合在大功率、高温和高频环境下应用,也是目前产业化程度最高的三代半材料,其产品应用场景已覆盖电源/功率因数校正(PFC)、光伏、新能源汽车/充电桩、风能、轨道交通、智能电网等诸多领域.与传统的硅基器件相比,碳化硅制造出的电力电子器件体积更小...     

可延展柔性光子/电子集成器件及转印技术

基于无机半导体材料的光子/电子集成器件,是现代信息系统的重要组成部分和基础支撑.人与信息的交互融合是信息技术的主要发展方向,这种新的信息交互手段对电子集成器件提出了可延展柔性化的需求,以实现物理世界、信息数据和人类社会资源的综合利用.可延展柔性化的集成器件,可突破传统刚性无机集成器件不可变形、无法与人体曲面环境集成的瓶颈,极大拓展了传统半导体器件的物理形态及应用范围,也必将在健康医疗、脑机融合、物联网等领域产生巨大影响.本文对可延展柔性光子/电子集成器件的基本原理和设计方法进行了详细介绍,并以大脑、心脏和皮肤可集成的可延展柔性无机电子集成器件为例展示了其在生物医疗方面的应用价值,然后介绍了可延展柔性光子/电子集成器件的转印制备技术,最后展望了其未来发展方向.     

一种新型双材料双栅的MOSFET器件的性能研究

为了给新型场效应晶体管的工艺制造和设计提供新的设计思路和依据,文章以金属-氧化物-半导体场效晶体管(MOSFET)为研究对象,提出了一种新型双材料双栅MOSFET器件的设计方案.该器件采用具有宽禁带、高饱和电子速度、高热导性、高温工作等性能优势而在微电子领域和光电子领域广泛应用的新型半导体材料GaN.同时,通过仿真模拟对器件的转移特性、输出特性,跨导特性、电容特性以及器件的电学特性与温度的关系进行了分析.结果 表明,器件性能随着温度升高而退化的主要原因是迁移率和载流子饱和速率随温度的变化,且器件具有较好的亚闽值摆幅和开关电流比,适合于未来低功耗应用领域.     

上海师范大学物理系科研简介

<正>上海师范大学数理学院物理系科研工作依托"光电材料与器件实验室"开展,分为凝聚态物理、原子分子物理及光学等研究领域,在多电子原子物理、量子信息、多铁物理、宽禁带半导体物理等多个方向上具有明显的研究特色。一、铁电、压电、磁电等信息功能材料与器件中的关键科学问题研究我们围绕铁电、压电、磁电复合及光流明材料与器件中的关键科学问题开展研究,建立材料结构-性能-器件间的内在关系,研制了新型弛豫铁电单晶变压器、环境友好的高应变驱动器及高灵敏度的弱磁探测器件,并致力于探索增强相关效应间耦合的新途径,推进器件应用。     

Strong quantum-confined Stark effect in germanium quantum-well structures on silicon

Silicon is the dominant semiconductor for electronics, but there is now a growing need to integrate such components with optoelectronics for telecommunications and computer interconnections. Silicon-based optical modulators have recently been successfully demonstrated; but because the light modulation mechanisms in silicon are relatively weak, long (for example, several millimetres) devices or sophisticated high-quality-factor resonators have been necessary. Thin quantum-well structures made from III-V semiconductors such as GaAs, InP and their alloys exhibit the much stronger quantum-confined Stark effect (QCSE) mechanism, which allows modulator structures with only micrometres of optical path length. Such III-V materials are unfortunately difficult to integrate with silicon electronic devices. Germanium is routinely integrated with silicon in electronics, but previous silicon-germanium structures have also not shown strong modulation effects. Here we report the discovery of the QCSE, at room temperature, in thin germanium quantum-well structures grown on silicon. The QCSE here has strengths comparable to that in III-V materials. Its clarity and strength are particularly surprising because germanium is an indirect gap semiconductor; such semiconductors often display much weaker optical effects than direct gap materials (such as the III-V materials typically used for optoelectronics). This discovery is very promising for small, high-speed, low-power optical output devices fully compatible with silicon electronics manufacture.     

A role for graphene in silicon-based semiconductor devices

As silicon-based electronics approach the limit of improvements to performance and capacity through dimensional scaling, attention in the semiconductor field has turned to graphene, a single layer of carbon atoms arranged in a honeycomb lattice. Its high mobility of charge carriers (electrons and holes) could lead to its use in the next generation of high-performance devices. Graphene is unlikely to replace silicon completely, however, because of the poor on/off current ratio resulting from its zero bandgap. But it could be used to improve silicon-based devices, in particular in high-speed electronics and optical modulators.     

二芳基芴类有机/聚合物半导体材料研究进展

在众多构建有机半导体材料分子结构中,二芳基芴类半导体凭借其特殊的电子、空间、位阻以及构象结构展现出良好的商业化前景.国内外研究学者致力于二芳基芴类电致发光小分子与聚合物半导体材料的研究,大量二芳基芴类电致发光小分子与聚合物半导体材料,包括电致发光材料、载流子传输材料、磷光器件的主体材料和电存储材料等已经得到了报道.文中以作者课题组的工作为主线系统总结了二芳基芴类有机/聚合物光电材料的分子结构、性质、及其应用等方面的进展,并展望了二芳基芴类有机/聚合物半导体材料未来发展的趋势与脉络.     

第三代半导体辐射探测器研究进展

 以氮化镓（GaN）、碳化硅（SiC）、金刚石等为代表的第三代半导体具有大的禁带宽度、高击穿电场、高饱和电子速率、高热导率以及具有高的位移阈能,耐高温、耐辐照能力,在核装置运行监测、空间探测、高能粒子物理探测等领域具有重要的应用潜力。介绍了第三代半导体的相关性质、辐射探测器主要制备方法以及不同类型辐射探测器的研究进展,展望了第三代半导体在辐射探测方面的发展趋势。提出第三代半导体辐射探测器的出现必然会促进核科学、空间探测、粒子及高能物理等方面的研究,对于国家提升核心竞争力具有重要的推动作用。     

Flexible metal-oxide devices made by room-temperature photochemical activation of sol-gel films

Amorphous metal-oxide semiconductors have emerged as potential replacements for organic and silicon materials in thin-film electronics. The high carrier mobility in the amorphous state, and excellent large-area uniformity, have extended their applications to active-matrix electronics, including displays, sensor arrays and X-ray detectors. Moreover, their solution processability and optical transparency have opened new horizons for low-cost printable and transparent electronics on plastic substrates. But metal-oxide formation by the sol-gel route requires an annealing step at relatively high temperature, which has prevented the incorporation of these materials with the polymer substrates used in high-performance flexible electronics. Here we report a general method for forming high-performance and operationally stable metal-oxide semiconductors at room temperature, by deep-ultraviolet photochemical activation of sol-gel films. Deep-ultraviolet irradiation induces efficient condensation and densification of oxide semiconducting films by photochemical activation at low temperature. This photochemical activation is applicable to numerous metal-oxide semiconductors, and the performance (in terms of transistor mobility and operational stability) of thin-film transistors fabricated by this route compares favourably with that of thin-film transistors based on thermally annealed materials. The field-effect mobilities of the photo-activated metal-oxide semiconductors are as high as 14 and 7?cm(2)?V(-1)?s(-1) (with an Al(2)O(3) gate insulator) on glass and polymer substrates, respectively; and seven-stage ring oscillators fabricated on polymer substrates operate with an oscillation frequency of more than 340?kHz, corresponding to a propagation delay of less than 210?nanoseconds per stage.     

Electronic measurement and control of spin transport in silicon

The spin lifetime and diffusion length of electrons are transport parameters that define the scale of coherence in spintronic devices and circuits. As these parameters are many orders of magnitude larger in semiconductors than in metals, semiconductors could be the most suitable for spintronics. So far, spin transport has only been measured in direct-bandgap semiconductors or in combination with magnetic semiconductors, excluding a wide range of non-magnetic semiconductors with indirect bandgaps. Most notable in this group is silicon, Si, which (in addition to its market entrenchment in electronics) has long been predicted a superior semiconductor for spintronics with enhanced lifetime and transport length due to low spin-orbit scattering and lattice inversion symmetry. Despite this promise, a demonstration of coherent spin transport in Si has remained elusive, because most experiments focused on magnetoresistive devices; these methods fail because of a fundamental impedance mismatch between ferromagnetic metal and semiconductor, and measurements are obscured by other magnetoelectronic effects. Here we demonstrate conduction-band spin transport across 10 mum undoped Si in a device that operates by spin-dependent ballistic hot-electron filtering through ferromagnetic thin films for both spin injection and spin detection. As it is not based on magnetoresistance, the hot-electron spin injection and spin detection avoids impedance mismatch issues and prevents interference from parasitic effects. The clean collector current shows independent magnetic and electrical control of spin precession, and thus confirms spin coherent drift in the conduction band of silicon.     

硅基半导体光电子材料的第一性原理设计

具有特定功能的半导体材料的计算设计，是计算材料科学的一个重要研究领域．由于半导体的诸多性质取决于价带顶和导带底的电子态及其中的载流子分布，因此带隙的大小和能带极值的对称性便成为半导体材料设计最受关注的问题．为了进一步解决硅基光电子集成（OEIC）技术发展的瓶颈．设计具有直接带隙特性的硅基新材料并使其成为有效的光发射体，是一项富有挑战性的工作．本文在分析大量半导体能带结构的基础上，给出类sp系列半导体由间接带隙过渡到直接带隙的主要物理机制，并以对称性概念、芯态效应和电负性差效应为基础，提出一种新的直接带隙半导体材料设计方案．根据这个方案所表达的设计思想，我们对当前十分受关注的硅基光发射材料进行了计算设计．结果发现，用VI族元素在硅生长时进行周期性插层的、具有正交和四角点群对称性的人工微结构材料VIA／Sim／VIB／Sim／VIA具有直接带隙特性．其中当m=5或奇数时，材料有四角结构对称性，而m=6或偶数时是正交结构对称性．VI“。。是在〈001〉生长方向生长的单层VI族元素．这类材料的优点在于可自然地与硅实现晶格匹配，与微电子技术相兼容，并可较容易的用现行的MBE、MOCVD或UHV-CVD生长方法实现．预期这类新材料及其相应器件的研制开发．将大大开拓全硅OEIC和硅光子集成（PIC）技术的进一步发展．     

Room-temperature fabrication of transparent flexible thin-film transistors using amorphous oxide semiconductors

Transparent electronic devices formed on flexible substrates are expected to meet emerging technological demands where silicon-based electronics cannot provide a solution. Examples of active flexible applications include paper displays and wearable computers. So far, mainly flexible devices based on hydrogenated amorphous silicon (a-Si:H) and organic semiconductors have been investigated. However, the performance of these devices has been insufficient for use as transistors in practical computers and current-driven organic light-emitting diode displays. Fabricating high-performance devices is challenging, owing to a trade-off between processing temperature and device performance. Here, we propose to solve this problem by using a novel semiconducting material--namely, a transparent amorphous oxide semiconductor from the In-Ga-Zn-O system (a-IGZO)--for the active channel in transparent thin-film transistors (TTFTs). The a-IGZO is deposited on polyethylene terephthalate at room temperature and exhibits Hall effect mobilities exceeding 10 cm2 V(-1) s(-1), which is an order of magnitude larger than for hydrogenated amorphous silicon. TTFTs fabricated on polyethylene terephthalate sheets exhibit saturation mobilities of 6-9 cm2 V(-1) s(-1), and device characteristics are stable during repetitive bending of the TTFT sheet.     

Solution-processed silicon films and transistors

The use of solution processes-as opposed to conventional vacuum processes and vapour-phase deposition-for the fabrication of electronic devices has received considerable attention for a wide range of applications, with a view to reducing processing costs. In particular, the ability to print semiconductor devices using liquid-phase materials could prove essential for some envisaged applications, such as large-area flexible displays. Recent research in this area has largely been focused on organic semiconductors, some of which have mobilities comparable to that of amorphous silicon (a-Si); but issues of reliability remain. Solution processing of metal chalcogenide semiconductors to fabricate stable and high-performance transistors has also been reported. This class of materials is being explored as a possible substitute for silicon, given the complex and expensive manufacturing processes required to fabricate devices from the latter. However, if high-quality silicon films could be prepared by a solution process, this situation might change drastically. Here we demonstrate the solution processing of silicon thin-film transistors (TFTs) using a silane-based liquid precursor. Using this precursor, we have prepared polycrystalline silicon (poly-Si) films by both spin-coating and ink-jet printing, from which we fabricate TFTs with mobilities of 108 cm2 V(-1) s(-1) and 6.5 cm2 V(-1) s(-1), respectively. Although the processing conditions have yet to be optimized, these mobilities are already greater than those that have been achieved in solution-processed organic TFTs, and they exceed those of a-Si TFTs (< or = 1 cm2 V(-1) s(-1)).