High throughput nanoimprint lithography for semiconductor memory applications
High throughput nanoimprint lithography for semiconductor memory applications
复制标题
用于半导体存储器应用的高通量纳米压印光刻
DOI：
10.1117/12.2260466
复制
发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Weijun Liu
中科院分区：
文献类型：
--
作者：
Zhengmao Ye;Wei Zhang;N. Khusnatdinov;T. Stachowiak;J. W. Irving;Whitney Longsine;M. Traub;B. Fletcher;Weijun Liu
压印光刻技术是一种很有前途的纳米尺度特征复制技术。对于半导体器件的应用，佳能沉积低粘度抗蚀剂上的一个领域，由外地的基础上使用喷射技术。将图案化的掩模降低到抗蚀剂流体中，然后抗蚀剂流体通过毛细作用快速流入掩模中的浮雕图案中。在该填充步骤之后，抗蚀剂在UV辐射下交联，然后去除掩模，在衬底上留下图案化的抗蚀剂。有两个关键组成部分，以满足生产量的要求，压印光刻。使用与许多沉积和蚀刻工艺已经完成的方法类似的方法，压印站可以集群以提高产量。FPA-1200 NZ 2C是一款四工位集群系统，专为大批量生产而设计。对于单个站，吞吐量包括开销、抗蚀剂分配、抗蚀剂填充时间（或铺展时间）、曝光和分离。抗蚀剂曝光时间和掩模/晶片分离是公知的处理步骤，其典型持续时间为0.10至0.20秒的量级。为了实现单个工作站每小时17片晶圆（wph）的总工艺吞吐量，需要在1.2秒内完成流体填充步骤。对于20 wph的吞吐量，灌装时间必须减少到只有一个1.1秒。有几个参数可以影响抗蚀剂填充。关键参数包括抗蚀剂液滴体积（越小越好）、系统控制（解决喷射后液滴扩散）、压印或DFI设计（加速液滴扩散）和材料工程（促进抗蚀剂和底层粘合层之间的润湿）。此外，即使对于边缘区域压印，也必须保持快速填充。在本文中，我们解决了所有这些参数的改进，首先使1.20秒的填充过程的设备一样的图案，并证明了这种能力，为全字段和边缘字段。两种场类型的非填充缺陷率均远低于1.0缺陷/cm 2。接下来，通过进一步减小液滴体积和优化液滴图案，证明了1.1秒的填充时间。
Imprint lithography is a promising technology for replication of nano-scale features. For semiconductor device applications, Canon deposits a low viscosity resist on a field by field basis using jetting technology. A patterned mask is lowered into the resist 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 17 wafers per hour (wph) for a single station, it is necessary to complete the fluid fill step in 1.2 seconds. For a throughput of 20 wph, fill time must be reduced to only one 1.1 seconds. 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 first enable a 1.20 second filling process for a device like pattern and have demonstrated this capability for both full fields and edge fields. Non-fill defectivity is well under 1.0 defects/cm2 for both field types. Next, by further reducing drop volume and optimizing drop patterns, a fill time of 1.1 seconds was demonstrated.