With respect to the achievable resolution, purely academic resolution values and industrially utilisable values represent two quite different aspects. Theoretically, resolutions of 2 nm are possible (single electron spot).
With CSAR e-beam resists, 6 nm lines can be achieved at a film thickness of 80 nm. Resolutions of up to 10 nm are possible with a film thickness of 180 nm.
With PMMA resists, similarly high resolutions are obtained at film thicknesses of max. 50 nm, but these structures can only be used with restrictions for commercial applications due to the process parameters (most of all the required high exposure doses). Resolutions up to 150 nm can be achieved with PMMA for films with 400 nm thickness as mostly utilised in industrial mask production.
Novolac-based negative e-beam resists allow a maximum resolution of 30 nm bars, while in industrial manufacturing processes, only 80 – 100 nm structures can be realised.
Overview E-beam FAQs