Terahertz Semiconductor Quantum Well Devices

For eventually providing terahertz science with compact and convenient devices,terahertz (1～10THz) quantum-well photodetectors and quantum-cascade lasers are investigated. The design and projected detector performance are presented together with experimental results for several test devices,all working at photon energies below and around optical phonons. Background limited infrared performance (BLIP) operations are observed for all samples (three in total) ,designed for different wavelengths. BLIP temperatures of 17,13, and 12K are achieved for peak detection frequencies of 9.7THz(31μm) ,5.4THz(56μm) ,and 3.2THz(93μm) ,respectively. A set of THz quantum-cascade lasers with identical device parameters except for doping concentration is studied. The δ-doping density for each period varies from 3.2 × 1010 to 4. 8 × 1010cm-2. We observe that the lasing threshold current density increases monotonically with doping concentration. Moreover, the measurements for devices with different cavity lengths provide evidence that the free carrier absorption causes the waveguide loss also to increase monotonically. Interestingly the observed maximum lasing temperature is best at a doping density of 3.6 × 1010cm-2.     

Terahertz Semiconductor Quantum Well Devices

For eventually providing terahertz science with compact and convenient devices,terahertz (1～10THz) quantum-well photodetectors and quantum-cascade lasers are investigated. The design and projected detector performance are presented together with experimental results for several test devices,all working at photon energies below and around optical phonons. Background limited infrared performance (BLIP) operations are observed for all samples (three in total) ,designed for different wavelengths. BLIP temperatures of 17,13, and 12K are achieved for peak detection frequencies of 9.7THz(31μm) ,5.4THz(56μm) ,and 3.2THz(93μm) ,respectively. A set of THz quantum-cascade lasers with identical device parameters except for doping concentration is studied. The δ-doping density for each period varies from 3.2 × 1010 to 4. 8 × 1010cm-2. We observe that the lasing threshold current density increases monotonically with doping concentration. Moreover, the measurements for devices with different cavity lengths provide evidence that the free carrier absorption causes the waveguide loss also to increase monotonically. Interestingly the observed maximum lasing temperature is best at a doping density of 3.6 × 1010cm-2.     

半导体器件欧姆接触中的扩散阻挡层

为提高半导体器件欧姆接触的可靠性，一般要在金属化系统中加扩散阻挡层。本文介绍了扩散阻挡层的种类及其特性，并进行了比较和讨论。最后给出了在实际成功应用的例子。     

微波半导体器件的计算机模拟

本文介绍半导体器件计算机模拟的物理模型和计算方法.以分析微波崩越二极管的大信号时间域模拟说明进行微波半导体计算机模拟的原理和过程,并给出对工作频率为40千兆赫的双漂移砷化镓崩越二极管进行计算机模拟的计算结果.     

半导体THz辐射的Monte Carlo模拟

本文介绍了作者开发的基于面向对象语言C++和统一建模语言UML的半导体输运及THz辐射的蒙特卡罗模拟软件,并用该软件模拟了在强超短脉冲激光(光生载流子密度10¹⁹cm^-3)及强电场 (100kV/cm) 作用下GaAs的THz时域波形和相应的半导体表面局域场.通过分析THz时域波形,我们发现强外加电场下的载流子速度过冲、载流子屏蔽(或器件反应过冲)是形成THz时域波形双极结构的原因.功率谱的分析表明增加外加电场有益于提高THz的低频成份的辐射,但对高频部分(＞6THz)影响不大.     

Parameters of Lateral and Unsteady Cord Currents in a Cylindrical Chalcogenide Glassy Semiconductor

Semiconductors - The heat-conduction equation describing the current cord in a semiconductor is approximately solved for a Ge–Sb–Te semiconductor system of cylindrical configuration. It...     

半导体器件计算机模拟的物理模型

本文分析评述半导体器件计算机模拟所使用的各等级物理模型,比较、阐明它们的基本假设和适用范围,并提出合理使用这些模型的指导性原则。     

亚微米半导体器件模拟方法的探索

本文综述了近十年来半导体器件模拟的发展概况，阐述了漂移扩散模型（ＤＤＭ）、流体动力学模型（ＨＤＭ）、玻耳兹曼模型（ＢＴＭ）、全量子模型（ＱＴＭ）的各自适用范围，概括了玻耳兹曼的一些新解法，ＨＤＭ，ＢＴＭ适合于亚微米半导体器件的模拟。     

太赫兹量子阱光探测器电子输运特性的MC模拟

半导体器件的MC(蒙特卡罗)模拟是深入研究小尺寸器件的物理过程中必不可少的工具.设计了一种基于三能带近似模型的MC平台,用来研究太赫兹场作用下GaAs/Al0.03Ga0.97As量子阱光探测器内部电子的输运特性.在这个平台的基础上,很好地研究了太赫兹作用下量子阱光探测器在低温和低电场时的电子输运特性.     

半导体器件模拟技术的研究

主要介绍了半导体器件模拟中常用的HD模型与DD模型和三角网格划分的常用算法。以泊松方程为例，简要说明了如何在三角网络上离散化方程。同时，介绍了几种求解非线形方程组常用的数值方法。     

Photoconductive Emission and Detection of Terahertz Pulsed Radiation Using Semiconductors and Semiconductor Devices

Recent studies on the techniques and development of photoconductive (PC) semiconductor devices for efficient generation and detection of terahertz (THz) pulsed radiation are reported. Firstly, the optimization of PC antenna design is discussed. The PC detection of THz pulsed radiation using low-temperature grown GaAs with 1.55-μm wavelength probe is then described. Finally, the enhancement of THz radiation from InSb by using a coupling lens and magnetic field is investigated. These results reveal valuable insights on the design of an efficient, compact, and cost-effective THz time-domain spectroscopy system based on 1.55-μm fs laser sources.     

pnpn结构器件模型的分析与模拟

将基本半导体方程归一化为奇异振动问题，采用渐近和数值技术，研究了ｐｎｐｎ结构器件模型解的分歧现象，确定了模型解唯一以及模型解出现Ｓ分歧的歧点，由此获得了Ｊ－Ｕ渐近解析表达式。实际例子表明，所获Ｊ－Ｕ的解析式与数值解结果一致。     

提高半导体器件欧姆接触可靠性的扩散阻挡层及其应用

为了提高半导体器件欧姆接触的可靠性，一般要在金属化系统中加扩散阻挡层。文中介绍了阻挡层的种类及其特性，并进行了比较和讨论。最后给出了在实际成功应用的例子。     

使用激光技术获得太赫兹电磁波

太赫兹电磁波有很多潜在的应用领域,但是至今还没有一种简便的产生太赫兹电磁波的方法.TOPTICA Photonics公司的Anselm Deninger和Thomas Renner对使用分布反馈二极管激光器和飞秒光纤激光器这两种产生太赫兹电磁波的方法进行了分析和比较.     

石墨烯太赫兹波段性质及石墨烯基太赫兹器件

石墨烯在太赫兹波段的优异性质,使其在太赫兹源、太赫兹探测和太赫兹调控三个方面都具备广阔的应用前景。主要对石墨烯在太赫兹波段的性质及石墨烯基太赫兹器件的相关研究进行了综述,并对石墨烯在太赫兹波段的应用前景进行了展望。在石墨烯太赫兹波段性质方面,主要介绍了石墨烯的电导模型、静态和超快光谱响应特性,以及表面太赫兹波辐射特性。在石墨烯基太赫兹器件方面,主要综述了基于光、电、磁调控的太赫兹主动器件,石墨烯基超材料的太赫兹调制器,基于阻抗匹配的减反射调控器件,以及可调太赫兹源器件的最新研究进展。     

Ultrafast Photo-Thermal Switching of Terahertz Spin Currents

Dissipationless and scattering-free spin-based terahertz electronics is the futuristic technology for energy-efficient information processing. Femtosecond light pulse provides an ideal pathway for exciting the ferromagnet (FM) out-of-equilibrium, causing ultrafast demagnetization and superdiffusive spin transport at sub-picosecond timescale, giving rise to transient terahertz radiation. Concomitantly, light pulses also deposit thermal energy at short timescales, suggesting the possibility of abrupt change in magnetic anisotropy of the FM that could cause ultrafast photo-thermal switching (PTS) of terahertz spin currents. Here, a single light pulse induced PTS of the terahertz spin current manifested through the phase reversal of the emitted terahertz photons is demonstrated. The switching of the transient spin current is due to the reversal of the magnetization state across the energy barrier of the FM layer. This demonstration opens a new paradigm for on-chip spintronic devices enabling ultralow-power hybrid electronics and photonics fueled by the interplay of charge, spin, thermal, and optical signals.     

半导体器件的发展动态

本文首先对国内半导体分立器件和半导体集成电路的质量水平做了估价,接着进行了国内半导体器件市场分析,讨论了器件销售所面临的困难和造成困难的原因,探讨了器件生产厂家的出路和发展方向,并对国产器件所存在的问题做了评述。文中还对半导体器件引进生产线情况做了介绍。本文在概述了分立器件的发展方向之后,重点阐述国内半导体集成电路的发展动态(我国IC工业发展现状、国内生产IC的主要品种、“七五”期间IC工业的发展及ASIC),并对国外IC发展动态做了扼要说明。     

半导体器件模拟中的一种三角网格生成方法

通过对半导体器件模拟中网格划分原理的分析 ,提出了一种基于标准单元结构的有限元三角网格生成方法 ,进行了面向对象的结构分析和编程实现 ,并成功地集成于半导体器件模拟软件 SMDS系统之中。结果表明 ,这种网格生成方法是行之有效的。     

半导体器件的贮存寿命

从失效机理出发,探讨了半导体器件的贮存寿命,提供了三种美国军用半导体器件长期贮存的实例.介绍了俄罗斯的规范,建议对超期复验中的有效贮存期作必要的修订.