Investigation of Thermal Analysis on the Process of Laser-Assisted Nanoimprinting Lithography

Abstract

The technique of laser-assisted nanoimprinting lithography (LAN) has been proposed to utilize an excimer laser to irradiate through a quartz mold and melts a thin polymer film on the substrate for micro- to nano-scaled fabrications. This study introduces optical multiple reflection theory to demonstrate both analytical and numerical modeling during the LAN process and to predict the thermal response theoretically. Furthermore, the capability of energy absorption for polymer resist is examined herein. The temperature of polymer resist with the capability of energy absorption is much higher than that without energy absorption. This study demonstrates the characteristics of the energy absorption for polymer materials could improve the performance of the LAN process for the reason that the thermally affected region is extremely limited.

Notes

Thermal properties (i.e., density, thermal conductivity, and specific heat) of silicon are taken from ref. [18]; the wave-dependent optical parameters for silicon are from ref. [19].

The density and heat capacity of PMMA are from ref. [20] and the thermal conductivity is adopted from ref. [21].

The index of refraction for PMMA is assumed independent of the incident wavelength and is set as 1.492 from ref. [22].

The properties of the quartz mold are used from the data sheets of fused silica by Corning Incorporated [23].