CSAR 62 as negative-tone resist for high-contrast e-beam lithography at temperatures between 4 K and room temperature

TL;DR

This study explores the use of CSAR 62 as a negative-tone resist for high-contrast electron-beam lithography across temperatures from 4 K to room temperature, highlighting its advantages at low temperatures for nanophotonic device fabrication.

Contribution

It demonstrates that CSAR 62 maintains high contrast and stability at low temperatures, making it suitable for in-situ nanostructure fabrication in cryogenic conditions.

Findings

High contrast of 10.5 at low temperatures

Resolution of 49 nm achieved at 4 K

Stable etch resistance across temperature range

Abstract

The temperature dependence of the electron-beam sensitive resist CSAR 62 is investigated in its negative-tone regime. The writing temperatures span a wide range from 4 K to room temperature with the focus on the liquid helium temperature regime. The importance of low temperature studies is motivated by the application of CSAR 62 for deterministic nanophotonic device processing by means of in-situ electron-beam lithography. At low temperature, CSAR 62 exhibits a high contrast of 10.5 and a resolution of 49 nm. The etch stability is almost temperature independent and it is found that CSAR 62 does not suffer from peeling which limits the low temperature application of the standard electron-beam resist PMMA. As such, CSAR 62 is a very promising negative-tone resist for in-situ electron-beam lithography of high quality nanostructures at low temperature.