Detailed characteristics of three classical rectangular convex corner compensation structures on（100） silicon substrates have been investigated, and their common design steps are summarized.By combining the basic me...Detailed characteristics of three classical rectangular convex corner compensation structures on（100） silicon substrates have been investigated, and their common design steps are summarized.By combining the basic method of a silicon wet anisotropic etching process, a general method of generating compensation structures for a rectangular convex corner is put forward.This calls for the following two steps：define the topological field and fit some borderlines together into practical compensation patterns.The rules, which must be obeyed during this process, are summarized.By introducing this method, some novel compensation patterns for rectangular convex corner structures are created on both（100） and（110） substrates, and finally simulation results are given to prove this new method＇s validity and applicability.展开更多
The etching characteristics of concave and convex corners formed in a microstructure by the intersection of {111} planes in wet anisotropic etchant are exactly opposite to each other. The convex corners are severely a...The etching characteristics of concave and convex corners formed in a microstructure by the intersection of {111} planes in wet anisotropic etchant are exactly opposite to each other. The convex corners are severely attacked by anisotropic Fetchant, while the concave corners remain unaffected. In this paper, we present a new model which explains the root cause of the initiation and advancement of undercutting phenomenon at convex corners and its absence at concave corners on {110} silicon wafers. This contrary etching characteristics of convex and concave corners is explained by utilizing the role of dangling bond in etching process and the etching behavior of the tangent plane at the convex corner. The silicon atoms at the convex edge/ridge belong to a high etch rate tangent plane as compared to {111} sidewalls, which leads to the initiation of undercutting at the convex corner. On the other hand, all the bonds of silicon atoms pertaining to concave edges/ridge are engaged with neighboring atoms and consequently contain no dangling bond, thus resulting in no-undercutting at concave edges/corners.展开更多
本文主要研究肺部CT图像中胸膜表面以及近胸膜肺结节的分割方法.由于胸膜粘附结点与肺实质周围的灰度值类似,因此通过边界跟踪获得的轮廓很可能会被过度分割.针对这个不足,本文提出了一种基于Graham扫描法和Harris角点检测算法的分割方...本文主要研究肺部CT图像中胸膜表面以及近胸膜肺结节的分割方法.由于胸膜粘附结点与肺实质周围的灰度值类似,因此通过边界跟踪获得的轮廓很可能会被过度分割.针对这个不足,本文提出了一种基于Graham扫描法和Harris角点检测算法的分割方法.该方法首先运用最大类间方差法将原CT图像转化为二值图像,并初步提取出肺实质部分的轮廓.然后运用凸包与凸缺陷以及角点检测方法对边界进行校正,从而得到完整的模板.最后根据校正后的模板分割出肺实质内部的所有结节候选点.本文对TCIA(The Cancer Imaging Archive)数据库中的263张CT样本进行实验并将实验结果与滚球算法、水平集方法以及边界逼近法得到的实验结果作对比.最后分析对比结果并证明本方法的有效性.展开更多
文摘Detailed characteristics of three classical rectangular convex corner compensation structures on（100） silicon substrates have been investigated, and their common design steps are summarized.By combining the basic method of a silicon wet anisotropic etching process, a general method of generating compensation structures for a rectangular convex corner is put forward.This calls for the following two steps：define the topological field and fit some borderlines together into practical compensation patterns.The rules, which must be obeyed during this process, are summarized.By introducing this method, some novel compensation patterns for rectangular convex corner structures are created on both（100） and（110） substrates, and finally simulation results are given to prove this new method＇s validity and applicability.
文摘The etching characteristics of concave and convex corners formed in a microstructure by the intersection of {111} planes in wet anisotropic etchant are exactly opposite to each other. The convex corners are severely attacked by anisotropic Fetchant, while the concave corners remain unaffected. In this paper, we present a new model which explains the root cause of the initiation and advancement of undercutting phenomenon at convex corners and its absence at concave corners on {110} silicon wafers. This contrary etching characteristics of convex and concave corners is explained by utilizing the role of dangling bond in etching process and the etching behavior of the tangent plane at the convex corner. The silicon atoms at the convex edge/ridge belong to a high etch rate tangent plane as compared to {111} sidewalls, which leads to the initiation of undercutting at the convex corner. On the other hand, all the bonds of silicon atoms pertaining to concave edges/ridge are engaged with neighboring atoms and consequently contain no dangling bond, thus resulting in no-undercutting at concave edges/corners.
文摘本文主要研究肺部CT图像中胸膜表面以及近胸膜肺结节的分割方法.由于胸膜粘附结点与肺实质周围的灰度值类似,因此通过边界跟踪获得的轮廓很可能会被过度分割.针对这个不足,本文提出了一种基于Graham扫描法和Harris角点检测算法的分割方法.该方法首先运用最大类间方差法将原CT图像转化为二值图像,并初步提取出肺实质部分的轮廓.然后运用凸包与凸缺陷以及角点检测方法对边界进行校正,从而得到完整的模板.最后根据校正后的模板分割出肺实质内部的所有结节候选点.本文对TCIA(The Cancer Imaging Archive)数据库中的263张CT样本进行实验并将实验结果与滚球算法、水平集方法以及边界逼近法得到的实验结果作对比.最后分析对比结果并证明本方法的有效性.
