Department of Mechanical Engineering, University of Colorado at Boulder, Boulder, CO 80309-0427, USA.
Nanotechnology. 2010 Mar 12;21(10):105301. doi: 10.1088/0957-4484/21/10/105301. Epub 2010 Feb 15.
We use immiscible polystyrene (PS)/polyacrylic acid (PAA) bilayer films as resist materials for nanoimprint lithography to probe the deformation profiles of the resist after the cavity filling process. By systematically varying the composition of the bilayers, we determined the deformation profiles of the bilayer resists at different depths after filling the 240 and 480 nm wide cavities. A single-peak deformation mode was observed for the bilayer films when the thickness of the top PS layer is less than the minimum thickness (H(c)) needed to completely fill the cavities. This is in good agreement with simulations based on pressure-driven viscous flow. However, for bilayers with a PS layer thickness close to H(c), a dual-peak deformation mode was observed near the entrance of the cavities, which is attributed to the stronger shear thinning of the polymer resist around these corners.
我们使用不混溶的聚苯乙烯（PS）/聚丙烯酸（PAA）双层膜作为抗蚀剂材料用于纳米压印光刻，以探测空腔填充过程后抗蚀剂的变形轮廓。通过系统地改变双层的组成，我们确定了填充 240nm 和 480nm 宽的空腔后双层抗蚀剂在不同深度的变形轮廓。当顶层 PS 层的厚度小于完全填充空腔所需的最小厚度（H(c)）时，双层膜表现出单峰变形模式。这与基于压力驱动粘性流的模拟很好地吻合。然而，对于 PS 层厚度接近 H(c)的双层膜，在空腔入口附近观察到双峰变形模式，这归因于这些拐角处聚合物抗蚀剂的剪切稀化更强。
