Authors: Z. Song, J. Lee and S. Park
Affilation: Louisiana State University, United States
Pages: 96 - 99
Keywords: simulation, demolding, local stress, demolding force, imprint lithography
Thermal imprint lithography is a highly potential technique utilizing molding to produce micro- and nano-structures with high throughput and at low cost. Extensive researches have been performed in understanding polymer flow behavior and cavity filling modes in order to improve the yield of the process. However, study of other critical processes, particularly demolding, is still lacking despite the fact that most of structural failures occur during this stage. With the increasing needs for high aspect ratio structures, in-depth understanding of fundamentals to the demolding process is imperative. In this paper, the demolding stage for the thermal imprint lithography was simulated using Finite Element Analysis software ANSYS 10.0. From simulation results, we found that the local stress in the PMMA layer concentrates close to the sharp corner, and moving along with the stamp. The highest local stress indicative of resist deformation during demolding shows two peaks, which indicates that demolding failure can occur at both the beginning and the end of the demolding . In addition, we systematically investigated the influence of different parameters. By comprehensive evaluation of simulation results, we will be able to understand the physical mechanisms and optimize the design of stamps and processes.