Prediction of resist sensitivity for 13.5-nm EUV and 6.x-nm EUV extension from sensitivity for EBL
Prediction of resist sensitivity for 13.5-nm EUV and 6.x-nm EUV extension from sensitivity for EBL
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根据 EBL 灵敏度预测 13.5 nm EUV 和 6.x nm EUV 扩展的抗蚀剂灵敏度
DOI：
10.1117/12.2011442
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
S. Tagawa
中科院分区：
文献类型：
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作者：
T. Oyama;A. Oshima;T. Dang;S. Enomoto;M. Washio;S. Tagawa
13.5 nm 极紫外光刻 (EUVL) 将很快应用于半导体的大批量制造，作为 ArF 准分子激光浸没光刻的替代品。最近，6.x nm（特别是 6.6-6.8 nm）曝光波长的潜在应用已被讨论为 EUVL 扩展。 6.x nm 曝光源目前正在开发中，因此使用传统曝光工具筛选光刻胶将加速 6.x nm EUVL 高灵敏度光刻胶的选择或新颖开发。在本研究中，使用 30 keV 和 75 keV 电子束光刻 (EBL) 工具评估了化学放大 (CA) 光刻胶 (OEBR-CAP112) 和非 CA 光刻胶（ZEP520A 和聚甲基丙烯酸甲酯）的灵敏度。就辐射化学而言，将获得的剂量/灵敏度（μC cm-2）转换为吸收剂量（格雷；Gy = J kg-1）。如果 EB 和 EUV 引发的化学反应相同，则 EB 和 EUV 所需的吸收剂量将是相似的值。假设抗蚀剂中所需的吸收剂量对于 EB 和 EUV 都显示相似的值，则预测了 EUV/软 X 射线（包括 6.x nm）的灵敏度。我们使用高度单色同步加速器辐射研究了抗蚀剂对 EUV/软 X 射线（包括 6.7 nm）的精确灵敏度。对于 CA 和非 CA 抗蚀剂，预测的灵敏度和实验获得的灵敏度彼此吻合良好。这些结果表明 EUVL 和 EBL 的抗蚀剂中诱导了几乎相同的化学反应。因此，我们发现我们可以根据 EBL 的曝光结果预测任意曝光波长下 EUV/软 X 射线的光刻胶灵敏度。
Extreme ultraviolet lithography (EUVL) at 13.5 nm will soon be applied in high-volume manufacturing of semiconductors, as a replacement to the ArF excimer laser immersion lithography. Recently, the potential application of exposure wavelengths of 6.x nm (particularly 6.6-6.8 nm) has been discussed as EUVL extension. The 6.x nm exposure source is currently under development, therefore screening of resists with conventional exposure tools will accelerate the selection or novel development of high sensitivity resists for 6.x nm EUVL. In the present study, the sensitivities of a chemically amplified (CA) resist (OEBR-CAP112) and non-CA resists (ZEP520A and poly(methyl methacrylate)) were evaluated with 30 keV and 75 keV electron beam lithography (EBL) tools. In terms of radiation chemistry, the obtained dose/sensitivities (μC cm-2) were converted into the absorbed doses (Gray; Gy = J kg-1). If EB- and EUV-induced chemical reactions are the same, the required absorbed doses for EB and EUV would be similar values. The sensitivities for EUV/soft X-rays including 6.x nm were predicted assuming the required absorbed doses in a resist would show similar values for both EB and EUV. We investigated precise sensitivities of the resists for EUV/soft X-rays including 6.7 nm using highly-monochromated synchrotron radiation. For both CA and non-CA resists, the predicted and experimentally obtained sensitivities agreed well with each other. These results suggested that almost the same chemical reactions are induced in resists for both EUVL and EBL. Hence, it was found that we can predict the resist sensitivities for EUV/soft X-rays at any exposure wavelength from the exposure results for EBL.