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

Step and flash imprint lithography (SFIL) is a technique that has die 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 angstroms. SFIL utilizes a low-viscosity, photosensitive silylated solution that exhibits high etch contrast with respect to organic films in O-2 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 11111 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. (C) 2001 American Vacuum Society.