Patterning nonflat substrates with a low pressure, room temperature, imprint lithography process

Abstract

Step and flash imprint lithography (SFIL) is a technique that has the potential to replace photolithography for patterning resist with sub-100 nm features. SFIL is a low cost, high throughput alternative to conventional photolithography for high-resolution patterning. It is a molding process in which the topography of a template defines the patterns created on a substrate. The ultimate resolution of replication by imprint lithography is unknown but, to date, it has only been limited by the size of the structures that can be created on the template. It is entirely possible to faithfully replicate structures with minimum features of a few hundred angströms. SFIL utilizes a low-viscosity, photosensitive silylated solution that exhibits high etch contrast with respect to organic films in O2 reactive ion etching. In this article we describe the SFIL process, the development of a multilayer etch scheme that produces 6:1 aspect ratio features with 60 nm linewidths, a method for patterning high-aspect-ratio features over topography, and a metal lift-off process. A micropolarizer array consisting of orthogonal 100 nm titanium lines and spaces fabricated using this metal lift-off technique is reported.

Letter from the editor

“…5), which are highly crystalline and have low solubility; APTMS (Fig. 5), which is a commonly used monomer to increase etch resistance to oxygen plasma etches40 but suffers from severe dewetting during spin‐coating; and 2,5‐dimethyl‐2,5‐hexanediol dimethacrylate (DHDMA) (Fig. 5), which is an acid cleavable crosslinker that demonstrates retention of functionality after hyperbranched polymer formation.…”

Applications of nanoimprint lithography/hot embossing: a review

“…In many occasions, imprint processes need to be undertaken at temperatures above the glass transition temperature T g of the resist [116][117][118]. Frequently, this temperature is well above 100°C.…”

Fabrication challenges for patterned recording media

“…The nanoimprinted resist is then typically used as an etch mask to transfer the pattern to the underlying substrate or film. One variation of this process, known as ''step and flash'', is outlined in [23] and shown in Fig. 5.…”