Modeling of profilometry with laser focus sensors
Modeling of profilometry with laser focus sensors
复制标题
使用激光聚焦传感器进行轮廓测量建模
DOI：
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
H. Baitinger
中科院分区：
文献类型：
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作者：
J. Bischoff;E. Manske;H. Baitinger
计量学在亚微米图案化中是至关重要的。特别是，线宽和重叠必须非常精确地测量。适当的计量技术是扫描电子显微镜和光学散射测量。后者是非侵入性的，高度精确的，并且能够实现层堆叠的光学横截面，但它需要周期性图案。扫描激光聚焦传感器是一种可行的替代方案，能够测量非周期性特征。确定边缘定位精度的衍射极限施加了严重的限制。结果表明，通过严格建模，可以大大提高精度。为此，一个完全矢量的2.5维模型已开发出严格的麦克斯韦求解器的基础上，并结合模型的扫描和各种自动对焦的原则。模拟结果与实验结果进行了比较。此外，直接利用模拟来提高边缘定位精度。
Metrology is of paramount importance in submicron patterning. Particularly, line width and overlay have to be measured very accurately. Appropriated metrology techniques are scanning electron microscopy and optical scatterometry. The latter is non-invasive, highly accurate and enables optical cross sections of layer stacks but it requires periodic patterns. Scanning laser focus sensors are a viable alternative enabling the measurement of non-periodic features. Severe limitations are imposed by the diffraction limit determining the edge location accuracy. It will be shown that the accuracy can be greatly improved by means of rigorous modeling. To this end, a fully vectorial 2.5-dimensional model has been developed based on rigorous Maxwell solvers and combined with models for the scanning and various autofocus principles. The simulations are compared with experimental results. Moreover, the simulations are directly utilized to improve the edge location accuracy.