Systematic study of the interdependence of exposure and development conditions and kinetic modelling for optimizing low-energy electron beam nanolithography

Abstract

In this work, we outline our extensive study of nanostructures with 15–35 nm lateral dimensions fabricated in PMMA employing 3–30 keV electrons. We have analysed the impact of the exposure voltage and dose, as well as development time and temperature, on the 3D morphology and quality of the nanoscale gratings in PMMA. We demonstrate that, in addition to the exposure conditions that are routinely optimized in standard EBL techniques, post-exposure resist processing is also a crucial factor and should be co-optimized when fabricating dense nanopatterns in the moderate to low voltage regimes. We analyze the potential of employing low-voltage exposures combined with cold development, and discuss factors affecting resolution and sensitivity of EBL at the nanoscale.