集成电路刻蚀过程三维仿真模型优化

集成电路三维刻蚀仿真模型的原始方案使用的是可变点阵的三维刻蚀仿真模型。但是在这种模型作用下新的刻蚀点空间坐标的误差会随着刻蚀点间距的不断增大而增大,最终的积累误差会导致仿真的效果变差。改进了原有算法,使用了新的固定点阵的离散化数学模型代替原有可变点阵的模型,大幅改善了刻蚀精度和显示效果。并给出了刻蚀仿真的结果并进行了讨论。     

集成电路刻蚀效果三维显示及其关键技术研究

集成电路仿真是集成电路制造的重要辅助方法,刻蚀过程是集成电路制造的一个重要的过程。使用三角形面片对刻蚀过程进行建模,并推导出连接不同面的平面和曲面的计算公式。最后给出了刻蚀显示仿真结果。结果显示,刻蚀结果清晰,绘制速度快,占用资源少,可以满足实际的刻蚀显示要求。     

基于SIMULINK的某型潜射水雷水下弹道仿真研究

对某型潜射水雷水下无动力运动过程中雷体的受力情况进行了研究,结合海流扰动模型给出了其水下运动的数学模型,并利用可视化仿真软件构造了系统仿真模型,对多种初始条件的水下不同深度的弹道参数进行了研究,给出了仿真结果和分析。     

大型飞行器的面向对象仿真研究

分析了大型飞行器动态飞行控制系统的数学模型,给出了其仿真系统的基本构成方案,并对制导与姿态控制的联合六自由度仿真、面向对象的仿真建模方法进行了研究.     

大型飞行器动态飞行控制系统的仿真研究

分析了大型飞行器动态飞行控制系统的数学模型,给出了其仿真系统的基本构成方案,并对制导与姿态控制的联合六自由度仿真、面向对象的仿真建模方法和一体化的仿真软件结构等进行了研究     

X舵潜艇空间运动仿真数学模型

潜艇水下运动是六个自由度的多姿态运动,建立空间运动方程数学模型是计算机仿真时对其进行比较准确的描述和对运动状态进行仿真研究的关键。该文在对X舵进行受力分析的基础上,由美国泰勒潜艇六自由度方程出发,导出适合X舵潜艇控制和仿真数学模型,并给出了该数学模型的微分形式。     

星载微波成像仪接收通道的仿真研究

星载微波成像仪接收通道即微波辐射计,是星载微波成像仪的核心部分。对其进行仿真研究的关键和基础是信号处理方法。给出了接收通道各环节的数学模型;采用快速离散富里叶变换处理信号;分析并缓解了由于离散富里叶变换带来的频率分辨率与样本点数之间的矛盾;以全功率微波辐射计为例进行了仿真研究并给出了结果。为进一步实现系统仿真调试和环境仿真调试奠定了基础,并为其它类型微波辐射计的仿真研究提供了借鉴。     

某新型燃气发生器发射过程药柱燃烧数值仿真

针对某新型导弹在发射过程中药柱燃烧规律的优化问题,建立了燃气发生器发射过程药柱燃烧仿真计算模型,预测发射过程中药柱燃烧的性能和参数.为了正确地仿真导弹发射过程,准确地计算导弹飞行轨迹,建立了适当的数学模型,并进行数值求解.根据内弹道相关的理论知识,在一定条件下,建立数学模型,采用Visual Studio开发平台进行编程,并采用龙格库塔法对仿真模型进行求解,实现了数值仿真,最后给出了计算机仿真结果曲线图.仿真结果与实际的实验数据基本吻合,运用在实际应用中,将大幅度地降低实验成本而且可以重复利用.     

基于MBTY的水下航行体控制系统的建模与仿真

水下航行体运动控制系统复杂,研制难度较大,利用三轴转台和MBTY软件对其进行建模及仿真研究是该文的主要目的。文中首先简要介绍了MBTY软件和三轴运动模拟转台,描述了水下航行体的动力学和运动学数学模型,给出了水下航行体控制系统的数学模型,并建立了相应的MBTY仿真图形模型,最后介绍了仿真过程和仿真结果。结果表明,利用“MBTY＋三轴转台”的模式进行运动控制系统的仿真,数据接口灵活、开放;通用和专业模块丰富;无需进行大量软硬件的开发,与“dSPACE＋Matlab／Simulink（或MATRIXx）＋三轴转台”的仿真模式相比具有一定的优势。     

超临界机组非线性模型参数估计与平衡点分析

在现代控制理论的基础上,以超临界直流发电机组的机炉协调多变量受控系统为研究对象,借鉴系统辨识与机理建模方法,结合采集的主要过程参数给出一种600MW超临界机组协调受控对象的非线性数学模型,并对其平衡点进行计算分析与仿真研究,证明其非线性数学模型的合理性,为超临界直流炉机组的研究提供一种参考方案.     

改进的硅各向异性腐蚀GPU并行模拟

硅各向异性腐蚀过程复杂,采用元胞自动机模拟硅各向异性腐蚀非常耗时。为了加速腐蚀模拟过程,研究了基于图形处理器(GPU)进行硅的各向异性腐蚀模拟。针对串行算法直接并行化方法存在加速效率低等问题,提出了一个改进的并行模拟方法。该方法增加了并行部分的负载,减少了内存管理的开销,从而提高了加速性能。实验证明该方法能够获得较理想的加速比。     

Modelling and simulation of forming process of the lithographically fabricated out-of-plane microlens using a cellular automata method

Three dimensional (3D) cellular automata (CA) model has been successfully applied in photoresist etching simulation in recent years. In this paper, a simplified 3D CA model is used to simulate the etching process of out-of-plane microlens fabricated on thick SU-8 photoresist. The simulation results are compared with experimental results. This CA model can be developed as a computer-aided design tool to predict the optimum process parameters during the forming of lithographically fabricated microlens.     

牺牲层二维腐蚀修正模型的研究

针对氢氟酸腐蚀氧化硅,深入研究了牺牲层腐蚀的原理。牺牲层腐蚀主要受扩散机制影响。把二维扩散方程中的扩散系数看作溶液浓度和温度的函数,建立了二维腐蚀修正模型。利用有限差分算法求解扩散方程,并使用C语言编程实现了对单开口、内外拐角等多种复杂组合结构腐蚀过程的模拟,使用MATLAB软件绘制腐蚀图形,最后将模拟结果与实验结果进行了对比,验证了模型的合理性。     

基于消息驱动机制的工作流仿真模型的设计与应用

将消息驱动机制仿真策略应用于企业经营过程重组的工作流仿真模型构建中,提出了一种基于消息驱动机制的工作流仿真模型方法,分析设计了该模型的工作流实体、工作项实体、消息体和仿真监控器,并对工作项实体的消息处理机制以及工作流仿真模型的仿真执行机制进行详细论述,给出了核心类的主要字段和方法.基于Visula C#编程,实例化验证...     

Free-Form Simulation of Sequential Etching and Surface Characterization for 3-D MEMS Fabrication

A new diffusion-based simulation model of isotropic wet etching and free-form surface characterization method for 3-D free-form microelectromechanical systems (MEMS) fabrication is presented in this paper. To simulate the etching process, a diffusion-based model solved by the finite-element method (FEM) has been developed, allowing extraction of more accurate etch-front data at discrete time steps. In the developed method, free-form MEMS objects are modeled as B-spline functions with material concentration. Finite elements are generated by discretization in the parametric domain of the free-form object and mapping back to the Euclidean space. Points on the etch front are extracted using a Z-map method. The extracted point data are characterized to obtain a B-spline representation of the etch-front surface. Examples from the isotropic etching simulation of 2-D and 3-D objects with both regular and free-form geometry are presented. The developed method allows the simulation of 3-D objects with free-form input and free-form mask opening and facilitates the simulation of sequential etching of free-form objects with irregular mask openings. This paper also discusses applications of the developed method in MEMS process planning that can be realized by taking advantage of the better control of geometry that it provides in MEMS fabrication.     

Micromachining of (hhl) silicon structures: experiments and 3D simulation of etched shapes

The micromachining of various (hhl) silicon plates in a 35% KOH-water etchant is studied. Experimental shapes for membranes and mesa etched with initially circular masks are discussed. Theoretical 3D etched shapes for such microstructures are derived from a numerical simulation based on the tensorial model for the anisotropic wet etching. Experimental and theoretical shapes show a fair agreement, indicating a satisfactory adjustment of the dissolution slowness surface related to the etching of silicon in KOH etchant. The interest of the 3D simulation for designing mask patterns is outlined.     

Three-dimensional simulation of sacrificial etching

Sacrificial etching is one of the most important process steps in micro-electro-mechanical systems technology, since it enables the generation of free-standing structures. These structures are often the main part of micro-mechanical devices, intended to sense or induce a mechanical movement. The etching process transforms an initial multi-segmented geometry and depends on material properties and several process conditions. One of the crucial issues for etching is the etching selectivity on different materials. The major task for the simulation is to give an answer, how sacrificial layer surfaces regress in time under the influence of process parameters and to which magnitude surrounding material segments are affected by the etching process. For this purpose we have developed a fully three-dimensional topography simulation tool, Etcher-Topo3D, which is capable to deal with realistic process conditions. The main concept is demonstrated in this work. During simulation the topography of the initial multi-segment geometry is changed which is handled by a level-set algorithm. After a simulation is finished, the level-set representation has usually to be converted back to a mesh representation to enable further analysis. To illustrate the main features of our simulation tool several examples of MEMS structures with a sacrificial layer are presented.     

基于晶格结构的单晶硅异向腐蚀的计算机模拟

单晶硅异向腐蚀技术是制造三维MEMS微结构的重要加工技术。由于单晶硅异向腐蚀加工过程具有低成本和可用于大批量生产的特点,因而得到了广泛的应用。但由于加工是在微米/纳米尺度上进行,使得加工过程难以控制,加工结果难以观测,因此传统的MEMS微结构的研制需要经过反复的试制和修改过程,使得研制周期长、生产质量难以保证。引入加工过程计算机模拟技术,可望大大地缩短MEMS微结构的研制周期,提高其产品质量。文章在研究单晶硅异向腐蚀机制的基础上,建立了基于晶格结构的腐蚀过程模型,模型较好地解决了模拟过程中高时空复杂性的关键技术问题,可在微机上运行,并取得了良好的模拟效果。