I-MECH partner INL presented the poster "A patterning strategy for large area arrays of high density
nanostructures”, by Carlos Calaza and Elisabete Fernandes, at NanoIL 2018.
A production-worthy method to implement high density arrays of sub-micron nanostructures at a wafer scale is proposed. It is based on a co-optimization of the layout design, the e-beam lithography exposure and the intermediate SiO2 hard mask used for the final silicon etch process. The great complexity of the e-beam lithography exposure required at this scale to directly obtain the desired geometries has been reduced by introducing an intermediate hard mask to get independent control of some of the pattern parameters through the fabrication process. Rather than using e-beam lithography to create a resist mask for the etch process, which results in unaffordable exposure times for complex geometries (large patterns of curved structures), a simplified e-beamlithography step has been developed to attain a primary resist mask with needed shape and periodicity, but smaller size.