半导体器件模拟中的有限元三角网格误差分析

本文阐述了半导体器件模拟中的有限元三角网格误差分析的基本原理,在分析比较了几种误差估计方法之后,选择了一种比较优秀的方法作为自适应网格生成的误差指示器。     

几何修型对JSM模型失速特性的影响研究

在使用非结构网格求解器WiseCFD-UG软件对NASA第三届高升力会议JSM模型进行数值模拟研究的过程中,发现前缘缝翼与主机翼交接处的几何修型方式对失速特性的模拟结果有较大影响。针对切缝与不切缝这两种不同的几何修型方式,分别生成了同等规模的非结构网格。两套网格得到的计算结果表明:大攻角下不切缝的几何修型方式得到的压力分布及升力系数与实验值吻合的更好,能够更好的模拟低速构型的失速特性。     

直角坐标系下非均匀FDTD网格生成系统

基于非均匀FDTD网格的电磁场模拟是一种解决诸多实际电磁场问题的通用、有效方法.本文介绍了在直角坐标系下非均匀FDTD网格图形生成系统,可以快速、高效地产生1D、2D、3D FDTD网格,展现物体的几何图形,还可以动态地、可视化地得到检查、调节和修改.作为检验,本文以一实际结构为例,产生并显示了其网格图形.     

CPU轴流风扇参数化设计模拟及其应用

 基于传统的风扇设计方法,提出了风扇参数化设计和流场分析程序.采用VB开发了CPU轴流风扇空气动力设计软件和风扇参数化设计模拟软件,使用者只需输入风扇的基本结构参数,便可由程序自动生成高质量的六面体网格,能自动进行批处理模拟和结果后处理.最后采用该软件快速对风扇的结构参数进行性能分析,加深了CPU风扇各主要技术参数在风扇整体性能中影响程度的认识,为进一步的优化设计提供了条件.实践证明该方法能大大提高风扇设计者的工作效率,具有重大工程应用价值.     

求解波导不连续性问题的二维有限元网格生成算法

网格是有限元仿真的基础,网格质量的好坏直接影响着后续数值计算分析结果的精确性。当分析矩形波导不连续性问题时,对不连续结构电场分布在传播方向的任意切面上完全相同的情况,可以用简化的二维模型得到仿真结果,即仅需进行二维有限元网格划分^[1]。由于波导不连续处电场发生变化,通常对不连续区域进行网格加密来保证求解的精度。文中提出了一种基于Delaunay算法的二维有限元网格生成算法,可以实现在电场发生不连续的区域自动进行网格加密,加密效果与COMSOL生成的网格基本一致。文中的加密算法生成的网格可以用于波导二维有限元仿真中。     

彩电机壳结构CAD(Ⅹ) 第十讲 彩电机壳有限元网格生成

本文详述彩电机壳有限元分析的网格生成,是彩电微机系统CEDS中结构分析子系统的一部分。     

一种多功能映射网格分方法

在有限元当中网格(包括影射网格和自由网格)划分对于计算结果的影响至关重要。提出一种多功能映射网格划分方法,该方法以平面的网格划分为基础,曲面和某些特殊实体的网格可以通过其投影面或基准面的网格划分数据自动生成。算例表明,该方法结构简单,适用范围广,通过合理规划可以得到质量良好的网格。     

数据处理、信息处理

0103211三维复杂外形非结构网格的生成及应用[刊]/刘学强//南京航空航天大学学报.—2000,32(5).—533～538(E)以 Delaunay 方法为基础生成了三维复杂外形的四面体非结构网格。这种方法的特点是先布结点,然后按 Delatmay 准则将其连接起来。与其他方法相比,其好处是能较好地根据计算需要控制网格点的疏密,提高计算效率,其运行过程也较稳定。在布点过程中采用了背景网格,使点的生成自动而合理。文末给出了 M6机翼和简化航天飞机的数值算例。参6Y2000-62051-1950103212虚拟/扩充现实(含4篇文章)=Dral Session C2:virtu-al/augmented reality[会,英]//Proceedings of 1999IEEE International Conference on Multimedia Computing     

基于数字地形图与分形理论的地形生成

提出了一种基于ASTER GDEM数字地形图与分形理论相结合的三维地形生成方法。首先利用数字地形图灰度值-高程值映射来得到图像像素对应的高程值,然后运用Diamond-Square算法来生成地形网格,最后对生成的地形进行真实感显示仿真并给出了实例。上述方法取得了较好的仿真效果,对地形模拟进行了有益的探索与尝试。     

微波管二维三角形网格自动划分及加密方法

基于波前推进法,实现了一种针对微波管二维模型的自动三角网格生成及加密方法。该方法包含了多种网格生成模式,不仅可以通过角度和边长等因素对网格生成进行控制,还能够对网格进行拓扑优化和光滑处理。通过多种微波管二维模型实例计算结果证明,该方法具有区域适应性好、边界网格质量高、自动化程度高、以及加密方便等特点。     

Solution of semiconductor equations using a fully adaptive mesh strategy

The letter presents a novel means of mesh adaption when the finite-element method is applied to the semiconductor equations. Using triangular elements it has the ability to avoid obtuse angles while still allowing flexibility in mesh design. The usefulness of the method is demonstrated by a simulation of an MOS device operating at a high drain voltage where generation due to impact ionisation becomes significant.     

半导体器件模拟软件的面向对象分析与设计

本文在对半导器器件模拟过程分析的了，提出了目前广为流行的器件模拟软件面向对象的设计和开发方法。由此获得的软件系统具有易使用、易维护、易扩展等显著优点，可适应半导体器件不断发展的需要。     

Characterization of Generation Lifetime and Surface Generation Velocity of Semiconductor Wafers by a Contactless Zerbst Method

A contactless Zerbst method has been developed to characterize the generation lifetime and the surface generation velocity of a semiconductor wafer. This characterization is unaffected by the gate leakage current or the device fabrication process. In this study, this contactless Zerbst method was used to characterize the generation lifetime and the surface generation velocity of a partially Au-doped Si wafer. The results demonstrate that the contactless Zerbst method is a powerful technique for characterizing the generation lifetimes and the surface recombination velocities of semiconductor wafers.     

A novel simulation methodology for full chip-package thermo-mechanical reliability investigations

A methodology for simulating the accurate 3D structural details of a non-planarized technology chips is presented. FEM is a powerful tool used for electrical, thermal and mechanical analysis in the microelectronics industry. Manual geometry and finite element mesh generation of a 3D non-planar chip topology is extremely tedious and time consuming. Therefore, a new method, which is automatic or semi-automatic, is required to drastically reduce the pre-processing effort required for finite element simulations. Our proposed approach uses a virtual semiconductor fabrication technique to create geometry and finite element mesh on complex chip topology features. A microscopic power metal stack of a power IC was simulated to demonstrate this new simulation methodology and the results are presented. These numerical simulations, which included the non-linear behavior in the matrix, show that the detailed information of the large stress and strain gradients in the micro-fields can be obtained.     

S波段GaN微波功率器件的研制

简要介绍了第三代新型半导体材料GaN的特点和优势,基于Agilent ADS微波仿真软件设计并实现了一款工作于S波段基于GaN的高效超宽带微波功率器件。测试结果表明,该器件适用于2.7～3.5GHz的超宽带,连续波和脉冲制式均可工作,在饱和状态下,输出功率大于15W,增益达到13dB,漏极效率超过45%,并在管壳内部实现了匹配和偏置电路,对GaN MOSFET微波功率器件小型化、超宽带、高增益和高效率的优异性能得以验证和实现。     

Fabrication and Circuit Modeling of NMOS Inverter Based on Quantum Dot Gate Field-Effect Transistors

This paper presents the fabrication of a negative-channel metal–oxide–semiconductor (NMOS) inverter based on quantum dot gate field-effect transistors (QDG-FETs). A QDG-FET produces one intermediate state in its transfer characteristic. NMOS inverters based on a QDG-FET produce three states in their transfer characteristic. The generation of the third state in the inverter characteristic makes this a promising circuit element for multivalued logic implementation. A circuit simulation result based on the Berkley simulation (BSIM) circuit model of the QDG-FET is also presented in this paper, predicting the fabricated device characteristic.     

Status and application of HgCdTe device modeling

In this article, device modeling refers to numerical simulation of semiconductor device physics to predict electrical behavior. The silicon integrated circuit industry provides the example for the use of technology computer-aided design to simulate wafer fabrication processes, and the electrical performance of devices and circuits. This paper first reviews semiconductor device modeling in general, then as applied in work supporting the development and analysis of HgCdTe infrared detectors. Example applications of one- and two-dimensional device modeling are simulation of a bias-selectable, integrated two-color detector, and two-dimensional effects on the spectral response of a HgCdTe detector with composition grading.     

A hydrodynamic transport model and its applications in semiconductor device simulation

In this paper, a generalized hydrodynamic model that includes four conservation equations for a general, position-dependent energy band structure and effective mass is presented. An analytical mobility model is extended to simulate two-valley semiconductor devices. A semiconductor device simulation package, DYNA, is introduced. Simulation results for both bulk materials and submicron-gate GaAs MESFETs show good agreement with experimental data and Monte Carlo device simulation results.     

3D-Monte Carlo study of short channel tri-gate nanowire MOSFETs

As a result of recent trends in processor speed and core temperature, III-V semiconductors have become a tempting replacement for Si in semiconductor logic. However, as device geometries shrink, the advantages of such a switch are put into question. In this paper we present a computational survey of III-V materials in a tri-gate nanowire MOSFET geometry as compared with Si to determine an optimal material choice for this geometry using a 3D semi-classical Monte Carlo simulation tool. We show that InSb and InAs show promise as future materials for next generation switching devices.