Reducing extreme ultraviolet mask three-dimensional effects by alternative metal absorbers
Reducing extreme ultraviolet mask three-dimensional effects by alternative metal absorbers
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通过替代金属吸收剂减少极紫外掩模三维效应
DOI：
10.1117/1.jmm.16.4.041002
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
E. Hendrickx
中科院分区：
文献类型：
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作者：
V. Philipsen;Kim Vu Luong;L. Souriau;A. Erdmann;Dongbo Xu;P. Evanschitzky;R. V. D. van de Kruijs;Arash Edrisi;F. Scholze;C. Laubis;M. Irmscher;Sandra Naasz;C. Reuter;E. Hendrickx
抽象。近年来，极紫外（EUV）光刻已经证明了不断缩小的特征尺寸的图案化（实现N7技术节点及以下），而EUV掩模保持不变，使用70 nm钽（Ta）基吸收剂。这导致了实验观察到的掩模三维（M3D）的影响，在晶圆级，这是由倾斜入射的EUV光和图案化的吸收体之间的相互作用，具有典型的厚度值的顺序上的几个波长。我们利用EUV掩模的吸收体材料的光学性质作为M3D缓解策略。使用严格的光刻模拟，我们筛选潜在的单元素吸收材料的光学特性和最佳厚度，最小的最佳焦点变化，通过在晶圆级的间距。此外，M3D缓解吸收体材料进行评估的工艺窗口比较代工厂N5特定的逻辑剪辑。为了验证严格的模拟预测和测试替代吸收体材料的加工可行性，我们选择了候选的单一元素镍和钴对晶片衬底进行实验评估。我们提出的薄膜特性，以及这些单元素候选吸收材料的第一次图案化测试。
Abstract. Over the recent years, extreme ultraviolet (EUV) lithography has demonstrated the patterning of ever-shrinking feature sizes (enabling the N7 technology node and below), whereas the EUV mask has remained unaltered, using a 70-nm tantalum (Ta)-based absorber. This has led to experimentally observed mask three-dimensional (M3D) effects at the wafer level, which are induced by the interaction between the oblique incident EUV light and the patterned absorber with typical thickness values on the order of several wavelengths. We exploit the optical properties of the absorber material of the EUV mask as an M3D mitigation strategy. Using rigorous lithographic simulations, we screen potential single-element absorber materials for their optical properties and optimal thickness for minimum best focus variation through pitch at the wafer level. In addition, the M3D mitigation by absorber material is evaluated by process window comparison of foundry N5-specific logic clips. To validate the rigorous simulation predictions and test the processing feasibility of the alternative absorber materials, we have selected the candidate single elements nickel and cobalt for an experimental evaluation on wafer substrates. We present the film characterization as well as the first patterning tests of these single-element candidate absorber materials.