硅基沉积氮化镓，碳化硅，Ⅲ-Ⅴ族及其合金材料研究进展

硅基沉积氮化镓,碳化硅,Ⅲ-Ⅴ族及其合金材料是近年来的研究热点．氮化镓,碳化硅及其Ⅲ—Ⅴ材料在光电子和电子元件领域有着广泛的应用．例如大功率,高速器件,大型激光器,紫外探测器等等．尽管硅基片具有低成本,大的尺寸和极好的电热导性能等优点,硅基片仍没有成为氮化镓,     

氮化镓材料专利计量分析及启示

<正>氮化镓(Gallium Nitride,Ga N)基半导体材料是继硅和砷化镓基材料后的新一代半导体材料,被称为第3代半导体材料。氮化镓材料由于具有禁带宽度大、击穿电场高、介电常数小、电子饱和漂移速度高、抗辐射能力强和良好的化学稳定性等独特的特性,在光电子器件和高温、高频大功率电子等微电子器件领域有广阔的应用前景[1.2]。氮化镓材料的应用首先是在发光器件领域取得重大突破的。1991年,日     

半导体所研制成功氮化镓基激光器

中科院知识创新工程重要方向项目“氮化镓基激光器（KGCX2-SW-115）”通过了专家验收。氮化镓基半导体材料是继硅和砷化镓基材料后的新一代半导体材料，被称为第三代半导体材料，它具有宽的带隙，优异的物理性能和化学性能，在光电子领域具有广泛的应用前景和研究价值。用氮化镓基半导体材料研制成的氮化镓基激光器在国防安全领域和光信息存储、激光全色显示、激光打印、大气环境检测、水下通信、双色激光探测等领域具有重要的应用价值。     

北京大学研制成功10nm碳纳米管CMOS器件

<正>近日,在北京市科委先导与优势材料创新发展专项支持下,北京大学彭练矛教授团队在全世界范围内首次成功研制出10纳米碳纳米管CMOS器件,与同尺寸硅基器件相比,该器件速度是其5倍,而功耗仅为1/5,并在世界上首次成功制备出含有100个晶体管的碳纳米管集成电路。课题的研究成果表明在10纳米以下技术节点,碳纳米管CMOS器件相对于硅基CMOS器件具有巨大优势,这将大大增强研究机构和芯片公司对     

碳化硅半导体技术及产业发展现状

<正>碳化硅半导体(这里指4H-Si C)是新一代宽禁带半导体,它具有热导率高(比硅高3倍)、与Ga N晶格失配小(4%)等优势,非常适合用作新一代发光二极管(LED)衬底材料[1]、大功率电力电子材料[2]。采用碳化硅作衬底的LED器件亮度更高、能耗更低、寿命更长、单位芯片面积更小,且在大功率LED方面具有非常大的优势。此外,碳化硅除了用作LED衬底,它还可以制造高耐压、大功率电力电子器件如肖特基二极     

消息报道

苏州纳米所利用氮化镓器件从事核应用研究取得系列成果氮化镓(GaN)是一种III/V直接带隙半导体,作为第三代半导体材料的代表,随着其生长工艺的不断发展完善,现已广泛应用于光电器件领域,如激光器(LD)、发光二极管(LED)、高电子迁移率晶体管(HEMT)等。GaN基材料的良好抗辐射性能和环境稳定性,使得其在核探测领域具有很好的应用前景,在新型核电池领域也具有巨大的应用潜力。因为GaN辐生伏特效应核电池     

硅基SiC薄膜制备与应用研究进展

碳化硅（SiC）材料具有极为优良的物理、化学及电学性能,可满足在高温、高腐蚀等极端条件下的应用,碳化硅还是极端工作条件下微机电系统（MEMS）的主要候选材料,成为国际上新材料、微电子和光电子领域研究的热点。同时,碳化硅有与硅同属立方晶系的同质异形体,可与硅工艺技术相结合制备出适应大规模集成电路需要的硅基器件,因此用硅晶片作为衬底制备碳化硅薄膜的工作受到研究人员的特别重视。本文综述了近年来国内外硅基碳化硅薄膜的研究现状,就其制备方法进行了系统的介绍,主要包括各种化学气相沉积（Chemical vapor deposition,CVD）法和物理气相沉积（Physical vapor deposition,PVD）法,并归纳了对硅基碳化硅薄膜性能的研究,包括杨氏模量、硬度、薄膜反射率、透射率、发光性能、电阻、压阻、电阻率和电导率等,以及其在微机电系统传感器、生物传感器和太阳能电池等领域的应用,最后对硅基碳化硅薄膜未来的发展进行了展望。     

电子信息材料

方大集团实现氮化镓基半导体材料产业化 方大集团率先在我国成功实现氮化镓基半导体材料产业化,并已成功投放市场,此举标志着我国氮化镓基半导体材料的产业化已经取得了重大突破。 氮化镓基半导体材料可制成高效蓝、绿、紫、白色发光二极管和激光器,以蓝绿光二极管为例,可用于大屏幕彩色显示、汽车照明和交通信号,以及光通讯等领域。 经过近一年的努力,方大公司已研究、开发和     

产业资讯

国内外新材料领域技术、产业、企业、市场、应用等最新发展动态。信息来自我刊特约通讯员、国内外各主要报纸、期刊、网站以及政府部门、信息机构、相关企业、科研单位等NEWS电子信息材料我国氮化镓基激光器研究获重大突破11月16日,由中国科学院半导体研究所承担的国家“863”重大项目“氮化镓基激光器”获得重大突破。在激光器结构设计、材料生长、腔面解理以及测试分析等方面攻克一系列技术难题,在国内首次成功研制了具有自主知识产权的氮化镓基激光器。该氮化镓基激光器采用多量子阱增益波导结构,激射波长为410nm,条宽5nm,条长800nm。…     

第3代半导体产业发展概况

<正>第3代半导体是指以氮化镓(GaN)、碳化硅(SiC)、金刚石、氧化锌(ZnO)为代表的宽禁带半导体材料,各类半导体材料的带隙能比较见表1。与传统的第1代、第2代半导体材料硅(Si)和砷化镓(GaAs)相比,第3代半导体具有禁带宽度大、击穿电场高、热导率大、电子饱和漂移速度高、介电常数小等独特的性能,使其在光电器件、电力电子、射频微波器件、激光器和探测器件等方面展现出巨大     

Silicon—a new substrate for GaN growth

Generally, GaN-based devices are grown on silicon carbide or sapphire substrates. But these substrates are costly and insulating in nature and also are not available in large diameter. Silicon can meet the requirements for a low cost and conducting substrate and will enable integration of optoelectronic or high power electronic devices with Si based electronics. But the main problem that hinders the rapid development of GaN devices based on silicon is the thermal mismatch of GaN and Si, which generates cracks. In 1998, the first MBE grown GaN based LED on Si was made and now the quality of material grown on silicon is comparable to that on sapphire substrate. It is only a question of time before Si based GaN devices appear on the market. This article is a review of the latest developments in GaN based devices on silicon.     

New nanocrystalline powder substrates for nitrides layer epitaxy

GaN and related III-V nitride materials have been applied for fabrication of electronic and optical devices. The most important factor limiting the mass production of devices based on III-V nitride materials is the high cost of substrates and the elaborate growth techniques. The lack of large, bulk GaN substrates causes that the epitaxial layer of nitrides must be grown on heteroepitaxial substrates. The most widely applied are monocrystalline sapphire, SiC and silicon substrates; but the question of cheap and available substrates for nitrides growth is still open.In this paper, authors present some results of the growth of nitrides layer by the metal-organic vapor-phase epitaxy (MOVPE) technique on new nanocrystalline powder substrates (compressed Al₂O₃+SiC). The influence of substrate composition (the amount of SiC powder) on the properties of the GaN layer are presented. Also the impact of the conditions of epitaxial process on properties of the nitride layers are discussed.     

硅衬底GaN基LED研究进展

由于硅具有价格低、热导率高、大直径单晶生长技术成熟等优势以及在光电集成方面的应用潜力,GaN/Si基器件成为一个研究热点.然而,GaN与Si之间的热失配容易引起薄膜开裂,这是限制LED及其它电子器件结构生长的一个关键问题.近年来,随着工艺的发展,GaN晶体质量得到大幅度的提高.同时不少研究小组成功地在Si衬底上制造出LED.介绍了GaN薄膜开裂问题及近期硅衬底GaN基LED的研究进展.     

Si Complies with GaN to Overcome Thermal Mismatches for the Heteroepitaxy of Thick GaN on Si

Heteroepitaxial growth of lattice mismatched materials has advanced through the epitaxy of thin coherently strained layers, the strain sharing in virtual and nanoscale substrates, and the growth of thick films with intermediate strain‐relaxed buffer layers. However, the thermal mismatch is not completely resolved in highly mismatched systems such as in GaN‐on‐Si. Here, geometrical effects and surface faceting to dilate thermal stresses at the surface of selectively grown epitaxial GaN layers on Si are exploited. The growth of thick (19 µm), crack‐free, and pure GaN layers on Si with the lowest threading dislocation density of 1.1 × 10⁷ cm^?2 achieved to date in GaN‐on‐Si is demonstrated. With these advances, the first vertical GaN metal–insulator–semiconductor field‐effect transistors on Si substrates with low leakage currents and high on/off ratios paving the way for a cost‐effective high power device paradigm on an Si CMOS platform are demonstrated     

Effects of SiC buffer layer growth temperature on the residual strain of GaN/SiC/Si thin films

Effects of SiC buffer layers were studied on the residual strain of GaN films grown on 3C-SiC/Si (111) substrates. It was clearly observed by Raman scattering measurement that the residual strain of the GaN/Si is reduced by inserting the SiC intermediate layer. Furthermore, residual strain within the GaN/SiC/Si films decreased when the growth temperature of the SiC buffer layer decreased. It was proposed that the irreversible creep phenomenon occurs during the high temperature growth of SiC, affecting nature of the residual strain within the SiC and the GaN layers.     

LED封装基板研究新进展

基板散热是LED散热的最主要途径,其散热能力直接影响到LED器件的性能和可靠性。总结了LED封装基板材料的性能,综述了金属基板、陶瓷基板、硅基板和新型复合材料基板的研究进展,展望了功率型LED封装基板的应用和发展趋势。综合表明,MCPCB,DBC,DAB,DPC等基板各具优势,但DPC基板各种制备工艺参数合适,特别是铝碳化硅基板(Al/Si C)有着低原料成本、高导热、低密度和良好可塑性的显著优势,有望大面积推广应用。     

Calculation of residual thermal stress in GaN epitaxial layers grown on technologically important substrates

A detailed investigation of residual thermal stress and misfit strain in GaN epitaxial layers grown on technologically important substrates is performed. The thermal stress is low when GaN is grown on AlN, SiC and Si, and relatively higher when Al₂O₃ substrate is used. The stress is compressive for AlN and Al₂O₃ and tensile for Si and SiC substrates. Residual thermal stress analysis was also performed for three layer heterostructures of GaN/AlN/6H-SiC and GaN/AlN/Al₂O₃. The stress remains the same when a sapphire substrate is used with or without an AlN buffer layer but reduces by an order of magnitude when a 6H-SiC substrate is used with an AlN buffer layer.     

Improved growth of GaN layers on ultra thin silicon nitride/Si (1 1 1) by RF-MBE

High-quality GaN epilayers were grown on Si (1 1 1) substrates by molecular beam epitaxy using a new growth process sequence which involved a substrate nitridation at low temperatures, annealing at high temperatures, followed by nitridation at high temperatures, deposition of a low-temperature buffer layer, and a high-temperature overgrowth. The material quality of the GaN films was also investigated as a function of nitridation time and temperature. Crystallinity and surface roughness of GaN was found to improve when the Si substrate was treated under the new growth process sequence. Micro-Raman and photoluminescence (PL) measurement results indicate that the GaN film grown by the new process sequence has less tensile stress and optically good. The surface and interface structures of an ultra thin silicon nitride film grown on the Si surface are investigated by core-level photoelectron spectroscopy and it clearly indicates that the quality of silicon nitride notably affects the properties of GaN growth.     

Silicon carbide and diamond for high temperature device applications

The physical and chemical properties of wide bandgap semiconductors silicon carbide and diamond make these materials an ideal choice for device fabrication for applications in many different areas, e.g. light emitters, high temperature and high power electronics, high power microwave devices, micro-electromechanical system (MEMS) technology, and substrates. These semiconductors have been recognized for several decades as being suitable for these applications, but until recently the low material quality has not allowed the fabrication of high quality devices. Silicon carbide and diamond based electronics are at different stages of their development. An overview of the status of silicon carbide's and diamond's application for high temperature electronics is presented. Silicon carbide electronics is advancing from the research stage to commercial production. The most suitable and established SiC polytype for high temperature power electronics is the hexagonal 4H polytype. The main advantages related to material properties are: its wide bandgap, high electric field strength and high thermal conductivity. Almost all different types of electronic devices have been successfully fabricated and characterized. The most promising devices for high temperature applications are pn-diodes, junction field effect transistors and thyristors. MOSFET is another important candidate, but is still under development due to some hidden problems causing low channel mobility. For microwave applications, 4H-SiC is competing with Si and GaAs for frequency below 10 GHz and for systems requiring cooling like power amplifiers. The unavailability of high quality defect and dislocation free SiC substrates has been slowing down the pace of transition from research and development to production of SiC devices, but recently new method for growth of ultrahigh quality SiC, which could promote the development of high power devices, was reported. Diamond is the superior material for high power and high temperature electronics. Fabrication of diamond electronic devices has reached important results, but high temperature data are still scarce. PN-junctions have been formed and investigated up to 400 ^∘C. Schottky diodes operating up to 1000 ^∘C have been fabricated. BJTs have been fabricated functioning in the dc mode up to 200 ^∘C. The largest advance, concerning development of devices for RF application, has been done in fabrication of different types of FETs. For FETs with gate length 0.2 μ m frequencies f_T = 24.6 GHz, f_{max (MAG)} = 63 GHz and f_{max (U)} = 80 GHz were reported. Further, capacitors and switches, working up to 450 ^∘C and 650 ^∘C, respectively, have also been fabricated. Low resistant thermostable resistors have been investigated up to 800 ^∘C. Temperature dependence of field emission from diamond films has been measured up to 950 ^∘C. However, the diamond based electronics is still regarded to be in its infancy. The prerequisite for a successful application of diamond for the fabrication of electronic devices is availability of wafer diamond, i.e. large area, high quality, inexpensive, diamond single crystal substrates. A step forward in this direction has been made recently. Diamond films grown on multilayer substrate Ir/YSZ/Si(001) having qualities close those of homoepitaxial diamond have been reported recently.     

Uniformity control of 3 inch GaN/InGaN layers grown in Planetary Reactors®

We present results obtained from a 2400G3HT reactor with a maximum wafer capacity of 8×3 inch. To achieve uniformity of the growth, we increased the temperature uniformity on each satellite to 0.9°C and that from satellite to satellite to 0.8°C. The optimum reactor geometry has been found by extensive modeling of the reactor design. Thus, an optimization of uniformity and efficiency has been achieved. GaN, InGaN/GaN multi quantum wells, GaN:Si, GaN:Mg and AlGaN were obtained on 5×3 inch substrates by simple scaling of the corresponding process parameters of the 6×2 inch configuration. We demonstrate GaN:Si and GaN:Mg doping uniformity with a standard deviation of less than 5%, with thickness uniformities of less than 1.7% standard deviation without any edge exclusion. InGaN/GaN, quantum well emission at 480 nm shows a standard deviation of 1–2% without rim exclusion. We grew AlGaN with about 10% Al content and less than 2% standard deviation in Al composition across the 3 inch substrate. Simple electroluminescence test structures, consisting of a GaN:Si buffer, followed by a five-period InGaN/GaN quantum well and covered by a GaN:Mg cap with emission wavelengths of about 460 nm show wavelength variations across 3 inch wafers of less than 3 nm. All these results demonstrate that the AIXTRON Planetary Reactor® is a very flexible tool for mass production application, especially with respect to upgrading the system to larger wafer diameters, as is already well known from the standard GaAs and InP applications that are available up to 5×8 inch configurations.