Resist Filling Study for UV Nanoimprint Lithography Using Stamps with Various Micro/Nano Ratios.

Minqi Yin,Haibin Wang,Hongwen Sun

doi:10.3390/mi9070335

Abstract

Mixed micro- and nanoscale structures are gaining popularity in various fields due to their rapid advances in patterning. An investigation in stamp resist filling with multiscale cavities via ultraviolet (UV) nanoimprint lithography (UV-NIL) is necessary to improve stamp design. Here, simulations at the level of individual features were conducted to explain different filling behaviors of micro- and nanoscale line patterns. There were noticeable interactions between the micro-/nanoscale cavities. These delayed the resist filling process. Several chip-scale simulations were performed using test patterns with different micro/nano ratios of 1:1, 1:2, and 1:3. There were some minor influences that changed the micro/nano ratios on overall imprint qualities. During the imprinting process, the pressure difference at the boundary between micro- and nanoscale patterns became obvious, with a value of 0.04 MPa. There was a thicker residual layer and worse cavity filling when the proportion of nanoscale structures increased.

Highlights

The combination of micro- and nanoscale structures has broad applications, including multiscale inverse pyramid structures for solar cells with high efficiency [1], or surface-enhanced Raman spectroscopy (SERS) to detect various substances [2]
Due to the difficulties in quantifying the minor interactions between the micro- and nanoscale cavities, three chip-scale stamps with different micro/nano ratios were arranged to clarify the influence of neighboring micro-/nanoscale features
From an overview of the three situations, it is obvious that the microscale region enjoyed a higher quality of cavity filling than the nanoscale region

Summary

Introduction

The combination of micro- and nanoscale structures has broad applications, including multiscale inverse pyramid structures for solar cells with high efficiency [1], or surface-enhanced Raman spectroscopy (SERS) to detect various substances [2]. Micro/nano structures based on polymer materials are gaining popularity because they are multifunctional and recyclable. Conventional patterning processes are complex and time-consuming. They cannot produce complex micro/nano patterns at the same time. Nanoimprint lithography (NIL) is an advanced pattern transfer technique to replicate extremely wide features from micrometer to sub-10 nanometer. There are two main variants of NIL: Thermal nanoimprint lithography (T-NIL) and ultraviolet (UV) nanoimprint lithography (UV-NIL). Though both techniques can replicate micro/nano features to the resist layer [5,6], UV-NIL does not require high temperatures and pressures. The guaranteed replication fidelity ensures that UV-NIL can mass-produce micro- and nanoscale structures

Methods

Results

Conclusion