节点文献
集成电路中版图处理及互连线优化技术的研究
Processing of Layout and Research on Interconnect Lines Optimization Technology for Integrated Circuit
【作者】 韩力英;
【作者基本信息】 河北工业大学 , 微电子学与固体电子学, 2011, 博士
【摘要】 随着集成电路发展到超大规模阶段,集成电路工艺进入到亚微米甚至纳米阶段,集成电路中互连线成为限制版图面积的主要因素,同时版图图像处理在集成电路性能提取和失效判别中越来越重要。本文主要研究了集成电路物理设计版图图像恢复技术、版图提取技术及布局布线算法问题,可以概括如下:探索不同的方法从模糊的与非门电路版图和集成电路版图恢复清晰的版图,其中包括Lucy-Richardson(LR)法复原,维纳滤波复原,拉格朗日乘法算子最小二乘方滤波复原,并观察各种方法对同一个与非门电路和集成电路版图恢复清晰图像的适用情况,确定各自优缺点,最终实现模糊集成电路版图恢复。研究了集成电路图像特征提取,实现导线、有源区及多晶硅等区域分离。利用阀值图像分割方法,对PMOS管、与非门版图和反相器版图图像进行了灰度处理,研究了集成电路各个扩散层、导线层的特点,根据灰度值提取出P掺杂,有源区,金属层,多晶硅等各个部分,可以确定集成电路设计构成和各部分功能。研制了波传播电路自动布线软件,其中采用版图中区域标志、自动寻找、避开障碍区域、布终点标志,并完成布线的回找等功能,开发了集成电路布局软件,完成单点及多点连接线自动布线。以遗传算法为基础研究了集成电路布图优化算法,优化集成电路布局。结合电源和地线网络的特性,通过对模块布局的改进来优化电源和地线网络的布图,使模块按照设定的优先级排布,实现模块化设计中VLSI占用面积的优化。利用蚁群算法并考虑到信号串扰,实现了两端线网和多端线网的优化布线。采用对下一个区域的选择和信息素更新两个因素,将信号的串扰融入蚁群布线算法过程中,按照信号传输时间最短,优化了集成电路的布线。主要创新点如下:1.将图像恢复方法应用于集成电路版图处理,并发现了噪声模糊图像进行复原时,LR方法基本恢复不出集成电路版图,维纳滤波的去噪声明显但是图像清晰度不够,拉格朗日乘法算子最小二乘方滤波复原版图清晰。2.独立编写布图优化、布线优化、自动布线软件。此软件具有很强的适用性及灵活性,达到商业软件的功能。
【Abstract】 With the development of integrated circuit to large scale stage, integrated circuit technology comes into sub-micron and even nano stage. Interconnect lines become the main restrictive factors of layout area in integrated circuit, at the same time the processing of layout image becomes more and more important in the extraction of performance and failure analysis on integrated circuit. This paper mainly studies the restoration and extraction technology of layout image and some placement and routing algorithms in the physical design of integrated circuit. This is as follows:Various methods including Lucy-Richardson(LR), the Wiener filter and Lagrangian least squares filtering, are explored to recover the clear layout from fuzzy NAND and other integrated circuit layout image. The applications and their advantages and disadvantages of various methods are given. Finally, the fuzzy integrated circuit image is recovered.Feature extraction of integrated circuit layout is researched. Wires, active area and polycrystalline silicon area and so on have been separated. The gray processing are finished for PMOS tubes, NAND and inverter layout using threshold image segmentation method. The features of each diffusion layer and conductor layer are studied. P doping, active area, metal layers, polycrystalline silicon layers and so on are extracted according to the grey value. Hereby, the compositions of IC design and functions of various parts can been determined.Wave propagation is analyzed to realize automatic routing software. The routing software on integrated circuit including regional marks, automatically searching, sheering obstacles area, determining the end point coordinates, returning to find the starting points is developed. A single-point and multi-points connection can be implemented by the software.IC placement optimization algorithm based on genetic algorithm is studied to optimize integrated circuit layout. Placement of power and ground network is optimized combined with the characteristics of the power and ground network by the improvement of module placement. Modules are set in according to priority order and the optimization area is obtained in the modular design of VLSI.The optimization routing in two-terminal wire and multi-terminal wires is achieved using the ant colony algorithm and considering the signal crosstalk. The ant algorithm is improved in two aspects of next region selection and pheromone updating. The improved algorithm with crosstalk minimum optimizes the routing result by the shortest time according to the signal transmission.Main innovation points as follows:Ⅰ. It is found that the integrated circuit layout almost can not been recovered from the fuzzy image in the present of noise by Lucy-Richardson method. The Wiener filter is an effect method for the denoising, but obviously it is not enough for receiving clear image. The Lagrange least squares filtering is the most for restoration of the integrated circuit layout.Ⅱ. Layout optimization, routing optimization and automatic routing software are finished independently. This software achieves functions of commercial software and has strong suitability and flexibility.
【Key words】 integrated circuits; noise; routing; layout; ant colony algorithm; genetic algorithm;