AlGaAs／InGaAs功率PHEMT用异质材料的计算机优化与器件实验结果

借助一新的工艺模拟与异质器件模型用ＣＡＤ软件──ＰＯＳＥＳ（Ｐｏｉｓｓｏｎ－ＳｃｈｒｏｅｄｉｎｇｅｒＥｑｕａｔｉｏｎＳｏｌｖｅｒ），对以ＡｌＧａＡｓ／ＩｎＧａＡｓ异质结为基础的多种功率ＰＨＥＭＴ异质层结构系统（传统、单层与双层平面掺杂）进行了模拟与比较，确定出优化的双平面掺杂ＡｌＧａＡｓ／ＩｎＧａＡｓ功率ＰＨＥＭＴ异质结构参数，并结合器件几何结构参数的设定进行器件直流与微波特性的计算，用于指导材料生长与器件制造。采用常规的ＨＥＭＴ工艺进行ＡｌＧａＡｓ／ＩｎＧａＡｓ功率ＰＨＥＭＴ的实验研制。对栅长０．８μｍ、总栅宽１．６ｍｍ单胞器件的初步测试结果为：ＩＤｓｓ２５０～４５０ｍＡ／ｍｍ；ｇｍ０２５０～３２０ｍＳ／ｍｍ；Ｖｐ－２．０－２．５Ｖ；ＢＶＤＳ５～１２Ｖ。７ＧＨｚ下可获得最大１．６２Ｗ（功率密度１．０Ｗ／ｍｍ）的功率输出；最大功率附加效率（ＰＡＥ）达４７％。     

半导体发光材料的新应用——视觉敏感GaAsP光敏二极管

本文讨论了半导体发光材料的新应用—ＧａＡｓＰ视觉敏感光敏二极管。这是在ｎ—ＧａＡｓＰ上制作浅结的光敏二极管，通过对研组份值、结深的控制，器件的｜△ＥＶ｜≤０．１，这意味着器件的光谱响应十分接近于人眼，其暗电流小于０．２ｐＡ／ｍｍ２，灵敏度为０．８μＡ／ｍｍ２。该光敏二极管已成功地应用于高级自动电子相机中。     

梁式引线GaAs混频二极管对

文中报导的砷化镓梁式引线反向并联二极管对,可应用于鉴相器、谐波混频器等宽带部件。该器件以半绝缘ＧａＡｓ为衬底,选择ＮｂＭｏ／ＧａＡｓ微合金形成肖特基势垒,ＳｉＯ２和聚酰亚胺双介质作为钝化保护膜,以及合理的工艺途径。器件抗烧毁能力强,可靠性好。其伏安特性ｎ因子小于１．１,结电容２Ｃｊ＝０．１～０．２ｐＦ,正向微分电阻为３～６Ω,分布电容较小,结电容差为ΔＣｊ≤０．０２５ｐＦ,正向电压差为ΔＶＦ≤２５ｍＶ。将该器件应用于１８～４０ＧＨｚ宽带分谐波混频器中,中频带宽为４～８ＧＨｚ,混频器的变频损耗低于２０ｄＢ,本振功率为１３ｄＢｍ。     

InP系波导和光电探测器单片集成

本文主要报道ＩｎＰ光波导和ＩｎＧａＡｓ－ＰＩＮ光电探测器的单片集成，包括材料生长、器件工艺、器件测试三个部份．器件的结构和制作方法较为简单，而代表器件性能的主要参数可与国外同类器件相接近，如光波导损耗最小为８．６ｄＢ／ｃｍ，器件正向压降为０．４～０．６Ｖ，反向击穿电压＞４０Ｖ，响应度～０．５Ａ／Ｗ，上升时间＜０．９ｎｓ．     

2.5Gb/s1.55μm InGaAsP/InP分布反馈激光器/电吸收调制器单片集成器件

本文在已经报道的采用直接集成方法制作的１．５５μｍＩｎＧａＡｓＰ／ＩｎＰ部分增益耦合ＤＦＢ激光器与电吸收调制器的单片集成器件的基础上,进一步对器件的性进行了改进,并采用标准１４脚碟型管壳对集成器件进行了封装。封装后的发射模块阈值电流约为２０￣３０ｍＡ,边模抑制比大于４０ｄＢ,耦合输出光功率大于２ｍＶ,在３Ｖ的反向调制民压下消光比约为１７ｄＢ。我们还在２．５Ｇｂ／ｓ波分复用系统上对集成器件进行了传输     

在1．8GHz频率下功率密度为2．8W／mm的4H－SiCMESFET

本文论述了使用４Ｈ－ＳｉＣ衬底及外延层制作ＭＥＳＦＥＴ的方法，测得了栅长为０．７μｍ、栅宽为３３２μｍ的ＭＥＳＦＥＴ的直流、Ｓ参数和输出功率特性。当Ｖｄｓ＝２５Ｖ时，电流密度约为３００ｍＡ／ｍｍ，最大跨导在３８～４２ｍＳ／ｍｍ之间；当频率为５ＧＨｚ时，该器件的增益为９．３ｄＢ，ｆｍａｘ＝１２．９ＧＨｚ。当Ｖｄｓ＝５４Ｖ时，功率密度为２．８Ｗ／ｍｍ，功率附加效率为１２．７％。     

2英寸GaAs快速热退火技术研究

为配合２０００门ＧａＡｓ超高速门阵列及ＧａＡｓ超高速分频器等２英寸ＧａＡｓ工艺技术研究，开展了２英寸ＧａＡｓ快速热退火技术研究。做出了阈值电压为０～０．２Ｖ，跨导大于１００ｍＳ／ｍｍ的Ｅ型ＧａＡｓＭＥＳＦＥＴ和夹断电压为－０．４～－０．６Ｖ，跨导大于１００ｍＳ／ｍｍ的低阈值Ｄ型ＧａＡｓＭＥＳＦＥＴ。     

2英寸GaAs快速热退火技术研究

为配合２０００门ＧａＡｓ超高速门列及ＧａＡｓ超高速分频器等２英寸ＧａＡｓ工艺技术研究，开展了２英寸ＧａＡｓ快速热退火技术研究，做出了阈值电压为０～０．２Ｖ，跨导大于１００ｍＳ／ｍｍ的Ｅ型ＧａＡｓＭＥＳＦＥＴ和夹断电压为－０．４～－０．６Ｖ，跨导大于１００ｍＳ／ｍｍ的低阈值Ｄ型ＧａＡｓＭＥＳＦＥＴ。     

高灵敏度低暗电流GaAs量子阱红外探测器

本文报道我们研制的高灵敏度、低暗电流的ＧａＡｓ量子阱长波长红外探测器的制备和性能．探测器具有５０个ＧａＡｓ量子阱和Ａｌ０．２８Ｇａ０．７２Ａｓ势垒，器件制成直径为３２０μｍ的台面型式单管．探测器的主要性能──响应率和探测率与偏置电流和工作温度关系很大．通过材料结构的精心设计和器件工艺的改进使探测器的性能进一步提高：探测峰值波长为９．２μｍ，工作温度为７７Ｋ时，峰值电压响应率为９．７e５Ｖ／Ｗ，峰值探测率超过１e１１ｃｍ·／Ｈｚ／Ｗ，暗电流小于０．１μＡ．     

全离子注入自对准难熔金属氮化物复合栅GaAs MESFET技术研究

本文研究了先进的全离子注入自对准难熔金属氮化物复合栅ＧａＡｓＭＥＳＦＥＴ场效应晶体管的工艺技术．首次使用Ｍｏ／ＺｒＮ作为复合栅的材料，ＡＩＮ薄膜作为器件介质钝化层，制作出了可用于ＧａＡｓ超高速集成电路的场效应晶体管，晶体管的跨导为１６０ｍＳ／ｍｍ，其栅漏反向击穿电压大于５Ｖ．     

Investigation of Mechanical and Electrical Characteristics for Cracked Conductive Particle in Anisotropic Conductive Adhesive (ACA) Assembly

In an anisotropic conductive adhesive (ACA) assembly, the electrical conduction is usually achieved with the conductive particles between the bumps of integrated circuit (IC) and corresponding conductive tracks on the glass substrate. Fully understanding of the mechanical and electrical characteristics of ACA particles can help to optimize the assembly process and improve the reliability of ACA interconnection. Most conductive particles used in the ACA assembly are with cracks in the metal coating of the particles after the ACA bonding. This paper introduced the fracture analysis by applying the cohesive elements in the numerical model of the nickel-coated polymer particle and further simulating the cracks initiation and propagation in the nickel coating during the ACA bonding. The simulation results showed that the stress distribution on the nickel-coated particle with cracks was significantly different from that on the nickel-coated particle without crack, indicating that the stress analysis by taking the crack into consideration is very important for the reliability assessment of the ACA interconnection. The stress analysis of cohesive elements indicated that the cracks initiated at the central area of the nickel coating and propagated to the polar area. Furthermore, by the introduction of a new parameter of the virtual resistance, a mathematical model was established to describe the electrical characteristics of the nickel-coated particle with cracks. The particle resistance of the nickel-coated particle with cracks was found to be much higher than that of the particle without crack in the optimized bonding pressure range, indicating that it is necessary to take the crack into consideration for the particle conduction analysis as well. Therefore, the fracture analysis on the conductive particle by taking the crack into consideration could accurately evaluate the reliability of ACA interconnection and avoid serious reliability issues.     

Experimental Analysis of Mechanical and Electrical Characteristics of Metal-Coated Conductive Spheres for Anisotropic Conductive Adhesives (ACAs) Interconnection

An accurate characterization for the deformation behavior of conductive particles is important: 1) to understand the anisotropic conductive adhesive (ACA) interconnection and 2) to optimize the ACA bonding parameter. This paper introduces an experimental technique, which has been developed to allow continuous monitoring of deformation characteristics of a single conductive particle. The load-deformation curve of a single conductive particle is measured, which provides the quantitative estimation of the mechanical and electrical characteristics of metal-coated polymer spheres used in ACAs. Based on the load-deformation result of a single conductive particle and the number of trapped particles on a bump, equivalent spring models are used to predict the deformation degree of conductive particles after flip chip assembly. For two kinds of conductive particles with different polymer cores, the mechanical and electrical characteristics of ACA interconnection were studied. Such results are used to further achieve a more sophisticated approach of the ACA bonding process and contact reliability.     

接触效应对小型半导体温差发电器性能的影响

针对小型半导体温差(TEG)发电器中接触热阻和接触电阻的影响进行了分析研究.结果表明,接触热阻和接触电阻只在2mm以内的电偶臂长度内有明显影响;在电偶臂长度小于1mm时,输出功率和热电效率均有一个急剧上升的变化阶段;当长度超过5mm后,输出功率和热电效率均趋于定值;在冷热端温度分别为283和383K,Z=0.0024K-1、电偶臂长为2mm、接触热阻比0.2和接触电阻比0.1条件下,热电功率约为4mW/mm2,热电效率约为3.5%,而理想无接触热阻和电阻的热电效率约为4.2%.由此可知,半导体温差发电器中接触热阻和接触电阻的影响不可忽视.     

钕掺杂对SnO_2·Co_2O_3·Nb_2O_5压敏电阻瓷电性能的影响

通过对样品的伏安特性,晶界势垒的测量和分析,研究了Nd2O3对SnO2·Co2O3·Nb2O5压敏电阻瓷电性能的影响。发现掺入x(Nb2O3)为0.050%的样品表现出最好的压敏性质,其压敏电压为460.69 V/mm,密度为6.812 g/cm3,非线性系数为18.7。为了说明电学非线性的起源,提出了SnO2压敏材料的一个缺陷势垒模型。     

底栅和顶栅结构全透明氧化锌薄膜晶体管的制备

报道了制备在50mm石英玻璃衬底上的透明氧化锌薄膜晶体管(ZnO-TFT),采用了底栅和顶栅两种结构进行比较.ZnO沟道层由射频磁控溅射方法制备,SiO2薄膜作为栅绝缘层.结果发现底栅结构的ZnO-TFT具有较好的电学性质,该器件工作在n沟道增强模式,具有较好的夹断效应和饱和特性,其场效应迁移率、阈值电压和电流开关比分别为18.4cm2/(V·s),-0.5V和104.顶栅结构的ZnO-TFT则工作在n沟道耗尽模式,没有明显的饱和特征.不同结构ZnO-TFT电学性质的差别可能是由于不同的ZnO/SiO2界面特性所致.两种结构的ZnO-TFT在可见光波段都有很高的光学透过率.     

GaAs微条粒子探测器的设计

介绍了最新研制成功的 Ga As微条粒子探测器的芯片设计和工艺设计。每一微条长度均为 1 70 0 0μm,宽度分别为 2 0、5 0、1 0 0、2 0 0和 3 0 0 μm。微条间距有 5 0、1 0 0、2 0 0和 3 0 0 μm四种 ,芯片面积为 5 .95 mm×1 7.0 0 mm。微条粒子探测器的反向击穿电压最高达 2 40 V,反向漏电流密度最低为 0 .0 2 5 μA/mm2。它对光照有强烈的敏感性。微条粒子探测器的辐照特性见其它论文报道     

1 W/mm power pseudomorphic HFET with optimised recess technology

The authors report record DC characteristics and RF performance of a power double heterostructure (DH) pseudomorphic (PM) InGaAs quantum well HFET. The device, with a 0.3×70 μm² gate, exhibits an intrinsic transconductance as high as 720 mS/mm, a maximum current density of ~1 A/mm and delivers a state-of-the-art output power density of 1 W/mm with 5.7 dB linear gain and 38% power added efficiency at 33 GHz. A detailed analysis of the technological aspects and electrical characteristics of the device is proposed to explain these excellent performances     

Effect of SiC Particles on the Electrical Conductivity of Epoxy Composites

In this paper, the behavior of the electrical conductivity of epoxy/silicon carbide (SiC) composites as a function of weight fraction and particle size of SiC at room temperature has been investigated. Composite samples were prepared by a mixture composed of the same amount of hardener and resin (5 mg) with different amounts (ranging from 5 mg to 7 mg) of silicon carbide powder with different grain sizes (400 and 800 grit). The conduction current was measured under different applied voltages from 1 to 10 kV (corresponding to applied electrical fields from 0.04 kV/mm to 0.4 kV/mm), and the composites microstructure was characterized by scanning electron microscopy. It was shown that the electrical conductivity of epoxy/SiC composites was found to increase when the weight fraction of SiC was increased and also to increase non-linearly as a function of the electrical field.     

5mm厚紫铜激光焊接接头组织及性能研究

为了研究离焦量对5mm厚紫铜激光焊接焊缝成形的影响和组织特征及性能,采用金相显微镜对焊缝组织及形貌进行分析,并对接头进行了拉伸及电导率测试。结果表明,在高离焦量绝对值时,易出现飞溅并造成焊缝表面孔洞,在离焦量0mm~-2mm范围内可获得成形良好的焊缝;焊缝纵截面柱状晶与焊接方向的角度由两侧的90°逐步降低为中间的0°,靠近焊缝上表面的柱状晶长度约为靠近下表面的柱状晶长度2.96倍,热影响区晶粒发生粗化,且离焦量+1mm对应的热影响区宽度最大;焊透情况下的不同离焦量对应的接头拉伸强度相当,可达母材的77.3%,离焦量0mm~-1mm对应的接头延伸率略高于离焦量-1mm~-4mm对应的接头延伸率,可达母材的54.9%;焊缝的电导率与母材几乎一样。该研究有利于获得成形良好的紫铜激光焊接接头。     

Theoretical and experimental responsivity of fir antenna coupled metal-insulator-metal detectors

In this work we report a complete theory of the metal-insulator-metal, antenna coupled, mm and sub-mm detectors. The voltage-power responsivity is simply derived from the geometrical antenna proprieties and the electrical junction characteristics. The calculated responsivity simply foresees our experimental results in the sub-mm — mm range and well fits all the previously reported data