High Resolution Nanoimprint for Nanophotonics
Abstract
Nanophotonics have drawn huge attention in recent years in various applications. Surface sensing technique, including surface-enhanced Raman spectroscopy (SERS), is an important topic of nanophotonics and has been widely investigated. The capability of SERS-active device depends on two main factors: good reproducibility and high enhancement factor. Ordered metallic nanostructures with high resolution are usually preferred for SERS application. Nanoimprint lithography can provide a low-cost and high resolution fabrication technique for SERS-active devices.
The objective of this research is to explore the application of nanoimprint lithography in SERS-active devices. This work begins with two issues of nanoimprint lithography: mold fabrication and throughput improvement. The potential of nanoimprint lithography depends on reliable mold fabrication. Two techniques are investigated, which are polyelectrolyte electrostatic self-assembly and controlled polymer reflow. Based on the observation of exceptional thermal stability of entangled polymer, step-and-repeat thermal nanoimprint lithography is developed. This technique significantly improves the throughput and enables the large scale application of thermal nanoimprint.
Ordered metallic nanostructures have been widely used as SERS-active substrates. In order to achieve high enhancement, extremely high resolution is needed, which can be limited by lithography technique. In this work, SERS-active devices based on gap surface plasmon polaritons are fabricated by nanoimprint lithography. 17 times more enhancement is achieved compared with conventional SERS-active devices on the same structure dimensions. This technique opens up possibilities of single molecule detection in the future.
Citation
Jiang, Youwei (2014). High Resolution Nanoimprint for Nanophotonics. Doctoral dissertation, Texas A & M University. Available electronically from https : / /hdl .handle .net /1969 .1 /152784.