High throughput Jet and Flash Imprint Lithography for semiconductor memory applications
High throughput Jet and Flash Imprint Lithography for semiconductor memory applications
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用于半导体存储器应用的高通量喷射和闪存压印光刻
DOI：
10.1117/12.2219161
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
Zhengmao Ye
中科院分区：
文献类型：
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作者：
Wei Zhang;B. Fletcher;E. Thompson;Weijun Liu;T. Stachowiak;N. Khusnatdinov;J. W. Irving;Whitney Longsine;M. Traub;Van Truskett;D. Labrake;Zhengmao Ye
压印光刻技术已被证明是一种有效的纳米级特征复制技术。喷射和闪光压印光刻（J-FIL*）涉及通过喷射技术在基板上沉积低粘度抗蚀剂的逐场沉积和曝光。有图案的口罩被放入液体中，然后通过毛细管作用迅速流入口罩中的浮雕图案。在这个填充步骤之后，抗蚀剂在紫外线辐射下交联，然后去除掩模，在基材上留下图案抗蚀剂。要满足压印光刻的吞吐量要求，有两个关键部件。使用与许多沉积和蚀刻工艺类似的方法，可以将压印站聚集在一起以提高吞吐量。FPA-1200NZ2C是一个为大批量生产而设计的四站集群系统。对于单个站，吞吐量包括开销、抗蚀剂分配、抗蚀剂填充时间（或扩散时间）、曝光和分离。抗蚀剂曝光时间和掩膜/晶圆分离是众所周知的处理步骤，其典型持续时间为0.10至0.20秒。为了实现单个工位每小时15片晶圆（wph）的总工艺吞吐量，必须在1.5秒内完成流体填充步骤。对于20 wph的吞吐量，填充时间必须减少到只有一秒。有几个参数可以影响抗填充。关键参数包括抗蚀剂滴量（越小越好）、系统控制（解决喷射后滴迹扩散问题）、压印或DFI设计（加速滴迹扩散）和材料工程（促进抗蚀剂和底层粘附层之间的润湿）。此外，即使是边缘场压印，也必须保持快速填充。在本文中，我们讨论了在所有这些参数中所做的改进，以实现对低于20nm器件的图案的1.50秒填充过程，并演示了这种能力在全场和边缘场。
Imprint lithography has been shown to be an effective technique for replication of nano-scale features. Jet and Flash* Imprint Lithography (J-FIL*) involves the field-by-field deposition and exposure of a low viscosity resist deposited by jetting technology onto the substrate. The patterned mask is lowered into the fluid which then quickly flows into the relief patterns in the mask by capillary action. Following this filling step, the resist is crosslinked under UV radiation, and then the mask is removed, leaving a patterned resist on the substrate. There are two critical components to meeting throughput requirements for imprint lithography. Using a similar approach to what is already done for many deposition and etch processes, imprint stations can be clustered to enhance throughput. The FPA-1200NZ2C is a four station cluster system designed for high volume manufacturing. For a single station, throughput includes overhead, resist dispense, resist fill time (or spread time), exposure and separation. Resist exposure time and mask/wafer separation are well understood processing steps with typical durations on the order of 0.10 to 0.20 seconds. To achieve a total process throughput of 15 wafers per hour (wph) for a single station, it is necessary to complete the fluid fill step in 1.5 seconds. For a throughput of 20 wph, fill time must be reduced to only one second. There are several parameters that can impact resist filling. Key parameters include resist drop volume (smaller is better), system controls (which address drop spreading after jetting), Design for Imprint or DFI (to accelerate drop spreading) and material engineering (to promote wetting between the resist and underlying adhesion layer). In addition, it is mandatory to maintain fast filling, even for edge field imprinting. In this paper, we address the improvements made in all of these parameters to enable a 1.50 second filling process for a sub-20nm device like pattern and have demonstrated this capability for both full fields and edge fields.