Extreme Ultraviolet Lithography (also known as EUV or EUVL) is an optical lithography technology using a range of extreme ultraviolet (EUV) wavelengths, roughly spanning a 2% FWHM bandwidth about 13.5 nm, to produce a pattern by exposing reflective photomask to UV light which gets reflected onto a substrate covered by photoresist. It is widely applied in semiconductor device fabrication process.
As of 2020, Samsung and Taiwan Semiconductor Manufacturing Company (TSMC) are the only companies who have used EUV systems in production, mainly targeting 5 nm. At the 2019 International Electron Devices Meeting (IEDM), TSMC reported use of EUV for 5 nm in contact, via, metal line, and cut layers, where the cuts can be applied to fins, gates or metal lines. At IEDM 2020, TSMC reported their 5 nm minimum metal pitch to be reduced 30% from that of 7 nm, which was 40 nm. Samsung’s 5 nm is lithographically the same design rule as 7 nm, with a minimum metal pitch of 36 nm.
—Wikipedia, “Extreme ultraviolet lithography“