Zhang Chuanwei, Liu Shiyuan, Shi Tielin, Tang Zirong
Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, China.
J Opt Soc Am A Opt Image Sci Vis. 2011 Feb 1;28(2):263-71. doi: 10.1364/JOSAA.28.000263.
The success of the model-based infrared reflectrometry (MBIR) technique relies heavily on accurate modeling and fast calculation of the infrared metrology process, which continues to be a challenge, especially for three-dimensional (3D) trench structures. In this paper, we present a simplified formulation for effective medium approximation (EMA), determined by a fitting-based method for the modeling of 3D trench structures. Intensive investigations have been performed with an emphasis on the generality of the fitting-determined (FD)-EMA formulation in terms of trench depth, trench pitch, and incidence angle so that its application is not limited to a particular configuration. Simulations conducted on a taper trench structure have further verified the proposed FD-EMA and demonstrated that the MBIR metrology with the FD-EMA-based model achieves an accuracy one order higher than that of the conventional zeroth-order EMA-based model.
基于模型的红外反射测量（MBIR）技术的成功在很大程度上依赖于红外计量过程的精确建模和快速计算，而这仍然是一个挑战，特别是对于三维（3D）沟槽结构。在本文中，我们提出了一种用于有效介质近似（EMA）的简化公式，该公式通过基于拟合的方法确定，用于3D沟槽结构的建模。我们进行了深入研究，重点关注拟合确定的（FD）-EMA公式在沟槽深度、沟槽间距和入射角方面的通用性，以便其应用不限于特定配置。在锥形沟槽结构上进行的模拟进一步验证了所提出的FD-EMA，并表明基于FD-EMA模型的MBIR计量精度比传统的基于零阶EMA模型的精度高一个数量级。
