超宽禁带半导体AlN功率电子学的新进展

以SiC和GaN为代表的第三代半导体功率电子学已成为当今功率电子学创新发展的主流,而有可能成为下一代固态功率电子学的超宽禁带半导体AlN功率电子学和同类的Ga₂O₃、金刚石功率电子学同样受到人们的关注。介绍了AlN功率电子学在AlN功率二极管、AlN功率高电子迁移率晶体管(HEMT)、AlN增强GaN HEMT和AlN的热管理应用等方面的最新进展,包括AlN异质多层外延结构、超晶格量子阱结构、AlN功率器件新结构设计、AlN新器件工艺、AlN超薄势垒层、AlN缓冲层、AlN钝化层、AlN耦合沟道层、AlN及其合金的热阻和AlN多晶陶瓷热导率等。分析评价了AlN功率电子学的发展、关键技术进步和发展态势。     

超宽禁带半导体AlN功率电子学的新进展(续)

以SiC和GaN为代表的第三代半导体功率电子学已成为当今功率电子学创新发展的主流，而有可能成为下一代固态功率电子学的超宽禁带半导体AlN功率电子学和同类的Ga₂O₃、金刚石功率电子学同样受到人们的关注。介绍了AlN功率电子学在AlN功率二极管、AlN功率高电子迁移率晶体管(HEMT)、AlN增强GaN HEMT和AlN的热管理应用等方面的最新进展，包括AlN异质多层外延结构、超晶格量子阱结构、AlN功率器件新结构设计、AlN新器件工艺、AlN超薄势垒层、AlN缓冲层、AlN钝化层、AlN耦合沟道层、AlN及其合金的热阻和AlN多晶陶瓷热导率等。分析评价了AlN功率电子学的发展、关键技术进步和发展态势。     

超宽禁带半导体金刚石功率电子学研究的新进展(续)

3功率晶体管与逻辑电路金刚石晶体管在功率电子学和微波电子学两大领域均有进展。在功率电子学领域向高击穿电压、高击穿场强、高温工作、低导通电阻、高开关速率和常关器件的方向发展。金刚石晶体管以各类FET为主,包括金属半导体场效应晶体管(MESFET)、MOSFET和JFET等,其沟道有两种:金刚石氢终端表面二维空穴气和p型掺杂层。     

超宽禁带半导体Ga2O3微电子学研究进展

半导体材料Ga2O3是继宽禁带半导体材料SiC/GaN之后新兴的直接带隙超宽禁带氧化物半导体,其禁带宽度为4.5~4.9eV,击穿电场强度高达8MV/cm(是SiC及GaN的2倍以上),物理化学稳定性高,在发展下一代电力电子学和固态微波功率电子学领域具有较大的潜力。自2012年第一只Ga2O3场效应晶体管诞生以来,Ga2O3微电子学的研究呈现快速发展态势。本文综述了β-Ga2O3单晶材料和外延生长技术以及β-Ga2O3二极管和β-Ga2O3场效应管等方面的研究进展,介绍了β-Ga2O3材料和器件的新工艺、新器件结构以及性能测试结果,分析了相关技术难点和创新思路,展望了Ga2O3微电子学未来的发展趋势。     

金刚石电子器件的研究进展

简述了金刚石半导体电气性质,即高击穿电场、宽带隙、高载流子饱和速度、高载流子迁移率和高热导率。回顾了金刚石器件的研究进程。讨论了器件的工作机理,包括掺杂和空穴积累层。详细描述了几种具有潜力的金刚石电子器件,如高压二极管和功率场效应管。尽管金刚石器件研究仍存在一些问题,如掺杂机理复杂,金刚石的单晶尺寸太小等,严重制约金刚石电子的进展,但是由于金刚石是超高功率和高温器件的优良半导体材料,具有替代行波管技术的潜力。当前,CVD金刚石已经大量用于微电子和光电子,包括激光二极管、微波器件、半导体散热器等。     

金刚石衬底GaN HEMT研究进展

SiC衬底GaN高电子迁移率晶体管(HEMT)综合了AlGaN/GaN异质结优异的输运特性与SiC衬底高导热性能,在高频、宽带、高效、大功率应用领域表现出显著的性能优势。但GaN外延材料中存在高密度的缺陷,影响了导电沟道的散热,散热问题成为影响GaN HEMT性能进一步发挥的主要障碍。本文分析了GaN外延材料高缺陷密度形成的原因,介绍了近年来国外正在开展的基于转移技术金刚石衬底GaN HEMT技术,解决GaN HEMT散热问题的研究进展。研究结果表明,基于转移技术的金刚石衬底GaN HEMT有望成为继SiC衬底GaN HEMT之后的下一代固态微波功率器件主导型器件技术。     

三代半导体功率器件的特点与应用分析

以S i双极型功率晶体管为代表的第一代半导体功率器件和以GaAs场效应晶体管为代表的第二代半导体功率器件为雷达发射机的大规模固态化和可靠性提高做出了贡献。近年来以S iC场效应功率晶体管和GaN高电子迁移率功率晶体管为代表的第三代半导体--宽禁带半导体功率器件具有击穿电压高、功率密度高、输出功率高、工作效率高、工作频率高、瞬时带宽宽、适合在高温环境下工作和抗辐射能力强等优点。人们寄希望于宽禁带半导体功率器件来解决第一代、第二代功率器件的输出功率低、效率低和工作频率有局限性以至于无法满足现代雷达、电子对抗和通信等电子装备需求等方面的问题。文中简要介绍了半导体功率器件的发展背景、发展过程、分类、特点、应用、主要性能参数和几种常用的半导体功率器件;重点叙述了宽禁带半导体功率器件的特点、优势、研究进展和工程应用;对宽禁带半导体功率器件在新一代雷达中的应用前景和要求进行了探讨。     

金刚石电子材料生长的研究进展

简述了金刚石兼具物理的和化学的优良性质,尤其是金刚石的半导体电气性质,即宽带隙、高击穿电场、高载流子迁移率和高热导率,成为固态功率器件最有前途的半导体材料之一。介绍了金刚石基的电子器件及其材料生长的研究进展,分析了金刚石膜的导电机理以及材料生长的新技术。重点介绍了采用包括微波等离子体化学汽相淀积(MPCVD)等方法制备金刚石膜、本征单晶生长、硼掺杂等技术。目前在直径为100~200 mm的硅衬底上,可以淀积均匀的超纳米结晶金刚石(UNCD)膜。此外,对金刚石电子学和光电子学的未来进行了展望。     

MPCVD生长半导体金刚石材料的研究现状北大核心

简要介绍了半导体金刚石材料优异的电学和光学性质、主要制备方法以及采用微波等离子体化学气相沉积(MPCVD)技术在制备高质量半导体金刚石材料方面的优势。重点就MPCVD技术在半导体金刚石材料的高速率生长、大尺寸生长、高质量生长以及电学掺杂等四个方面的研究现状进行了详细总结。详细探讨了目前半导体金刚石材料在大尺寸单晶金刚石衬底制备、高质量单晶金刚石外延层生长以及金刚石电学掺杂等方面还存在的一些基本问题。指出在大面积单晶金刚石衬底还没有实现突破的情况下,半导体金刚石材料和器件结构的生长模式。     

国外GaN功率器件衬底材料和外延技术研发现状

GaN基功率器件的衬底和外延技术的发展对于器件性能的提升和成本的降低起着非常重要的作用.介绍了国外SiC基、Si基以及新型金刚石基GaN功率器件衬底材料和GaN外延技术的研发现状.重点讨论了大尺寸衬底技术(6英寸SiC衬底、8英寸Si衬底)、GaN HEMT与Si CMOS器件异质集成技术以及金刚石基GaN HEMT材料集成技术的研发进展.分析了GaN功率器件材料技术的发展趋势,认为更大尺寸更高质量衬底和外延材料制作、外延技术的改进、金刚石等新型衬底材料研发以及GaN基材料与Si材料的异质集成技术等将是未来研究的重点.     

Diamond semiconductor and elastic strain engineering

Diamond,as an ultra-wide bandgap semiconductor,has become a promising candidate for next-generation microelec-tronics and optoelectronics due to its numerous advantages over conventional semiconductors,including ultrahigh carrier mo-bility and thermal conductivity,low thermal expansion coefficient,and ultra-high breakdown voltage,etc.Despite these ex-traordinary properties,diamond also faces various challenges before being practically used in the semiconductor industry.This review begins with a brief summary of previous efforts to model and construct diamond-based high-voltage switching diodes,high-power/high-frequency field-effect transistors,MEMS/NEMS,and devices operating at high temperatures.Following that,we will discuss recent developments to address scalable diamond device applications,emphasizing the synthesis of large-area,high-quality CVD diamond films and difficulties in diamond doping.Lastly,we show potential solutions to modulate diamond’s electronic properties by the“elastic strain engineering”strategy,which sheds light on the future development of diamond-based electronics,photonics and quantum systems.     

Metal Silicides: Active elements of ULSI contacts

As device dimensions scale to the 0.1 urn regime, the self-aligned suicide (SALICIDE) contact technology increasingly becomes an integral part of both the ultra-shallow junction and the metal oxide semiconductor field-effect transistor device itself. This paper will discuss the effect of suicide materials and formation processes on suicide stability, junction consumption, the ability to accurately profile shallow junctions, and contact resistance in series with the channel. The use of suicides as diffusion sources (SADS) provides an important pathway toward optimization of suicide technology. Diffusion of boron and arsenic from nearly epitaxial layers of CoSi₂, formed from bilayers of Ti and Co, offer good suicide stability, ultra-shallow, low-leakage junctions, and low contact resistance.     

固态微波电子学的新进展

固态微波电子学是现代电子学的重要分支之一,其基础材料已由第一代半导体Si和Ge、第二代半导体GaAs和InP,发展到第三代半导体GaN和SiC,石墨烯和金刚石等C基新材料正在进行探索性的研究,其加工工艺的尺寸也已进入纳米尺度,其工作频率已达到1 THz,应用的频率可覆盖微波毫米波到太赫兹.目前固态微波电子学呈多代半导体材料和器件共同发展的格局.综述了具有代表性的1 1类固态器件(RF CMOS,SiGe BiCMOS,RF LDMOS,RF MEMS,GaAs PHEMT,GaAs MHEMT,InP HEMT,InP HBT,GaN/SiC HEMT,GFET和金刚石FET)近几年的最新研究进展,详细介绍了有关固态微波电子学的应用需求、技术特点、设计拓扑、关键技术突破和测试结果,分析了当前固态微波电子学总的发展趋势和11类固态微波器件的发展特点和定位.最后介绍了采用3D异构集成技术的射频微系统的最新进展,指出射频微系统是发展下一代射频系统的关键技术.     

国外军事和宇航应用宽带隙半导体技术的发展

SiC和GaN等宽带隙半导体以其固有的高频、大功率、高温和抗恶劣环境应用潜力,在替代传统的Si和GaAs等器件应用于军事及宇航系统装备方面具有无可比拟的技术优势.概述了以SiC、GaN和金刚石等为代表的第三代半导体器件技术的发展现状,介绍了国外发达国家在发展宽带隙半导体技术上值得借鉴的一些做法,着重讨论宽带隙半导体技术对宇航及军事装备产生的重要影响,并展望了宽带隙半导体技术在宇航及军事应用中的发展前景.     

微波功率晶体管的发展与分析

本文阐述了国内外硅双极微波功率晶体管和砷化镓微波功率场效应晶体管的发展历史和现状,并分析了微波功率晶体管的发展特点。介绍了HBT,HFET,MISFET,金刚石、SiC电子器件,真空微电子器件等用于或将用于微波、毫米波功率领域中的情况。提出了发展微波功率晶体管的几点想法。     

Progress of power field effect transistor based on ultra-wide bandgap Ga2O3 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.     

Stable Electrical Operation of 6H–SiC JFETs and ICs for Thousands of Hours at 500 $^{circ}hbox{C}$

The fabrication and testing of the first semiconductor transistors and small-scale integrated circuits (ICs) to achieve up to 3000 h of stable electrical operation at 500degC in air ambient is reported. These devices are based on an epitaxial 6H-SiC junction field-effect transistor process that successfully integrated high-temperature ohmic contacts, dielectric passivation, and ceramic packaging. Important device and circuit parameters exhibited less than 10% of change over the course of the 500degC operational testing. These results establish a new technology foundation for realizing durable 500degC ICs for combustion-engine sensing and control, deep-well drilling, and other harsh-environment applications.     

Reliability issues of GaN based high voltage power devices

GaN based power devices for high efficiency switching applications in modern power electronics are rapidly moving into the focus of world wide research and development activities. Due to their unique material properties GaN power devices are distinguished by featuring high breakdown voltages, low on-state resistances and fast switching properties at the same time. Finally, these properties are the consequences of extremely high field and current densities that are possible per unit device volume or area. Therefore, in order to obtain very high performance, the material itself is stressed significantly during standard device operation and any imperfection may lead to wear out and reliability problems. Thus material quality, the specific epitaxial design as well as the device topology will directly influence device performance, reliability and mode of degradation. The paper will mainly discuss those degradation mechanisms that are especially due to the specific material combinations used in GaN based high voltage device technology such as epitaxial layer design, chip metallization, passivation schemes and general device topology and layout. It will then discuss technological ways towards engineering reliability into these devices. Generally, device designs are required that effectively minimize high field regions in the internal device or shift them towards less critical locations. Furthermore, an optimized thermal design in combination with suitable chip mounting technologies is required to enable maximum device performance.