Abstract

NANOIMPRINT LITHOGRAPHY: A REVIEW

Yash Gandhi*, Hiral Panchal, Mona Christian, Nisha Parikh, Palak Parikh

Department of Quality Assurance, Arihant School of Pharmacy & BRI, Adalaj, Gandhinagar, Gujarat, India

ABSTRACT

The Nanoimprint lithography (NIL) is a novel method of fabricating micro/nanometer scale patterns with low cost, high throughput and high resolution. It folds patterns by mechanical deformation of imprint resist and subsequent processes. The imprint resist is typically a monomer or polymer formulation that is cured by heat or UV light during the imprinting. Nanoimprint lithography was first invented by Prof. Stephen Chou and his students. It is a nonconventional, high-resolution lithographic method in which a surface pattern of a stamp is replicated into a material by mechanical contact and three dimensional material displacement. It is based on the principle of mechanically modifying a thin polymer film using a template (mold, stamp) containing the micro/nanopattern, in a thermo-mechanical or UV curing process. Distinct features for NIL involve two points: The contact nature of the process and direct mechanical deformation of the resist. Nanoimprint lithography has demonstrated 25 nm feature size, 70 nm pitch, vertical and smooth sidewalls, and nearly 90° corners. Four types of Nanoimprint lithography include Hot Embossing (Thermal Nanoimprint Lithography), UV Nanoimprint lithography, Jet and Flesh Imprint Lithography (Step and Flesh Imprint Lithography) and Reverse Nanoimprint lithography. Nanoimprint lithography process divided into 3 steps: Stamp Conditioning, Sample Preparation (Wafer Coating), Pre imprinting and Imprinting process. The ultimate resolution of Nanoimprint lithography could be sub -10 nm, the Imprint process is repeatable, and the mold is durable. Nanoimprint lithography has been successfully used for fabricating nanoscale photodetectors, silicon quantum-dot, quantum-wire, and ring transistors.

Keywords: Nanoimprint lithography; Stamp; Mold; Substrate.