https://wccftech.com/tsmc-ramps-volume-manufacturing-for-7nm-using-euv-scanners-expects-5nm-by-2020/

TSMC has started volume manufacturing of high-performance 7nm parts according to a report by DigiTimes. The manufacturing concern has been on a roll lately and is expected to beat Intel foundry for the first time in many years when its high-performance 7nm parts hit the market in 2H 2019 through AMD (Intel’s equivalent 10nm parts are expected to arrive later by the end of 2019). They have even started risk production of 5nm parts and expect volume production by 2020. Their dirty little secret? EUV.

It appears that TSMC did not make the same mistake Intel did and shifted to EUV directly from UV. Heres what this means. Wafers are etched using light and the minimum possible etch is the wavelength divided by 2. UV has a wavelength of 400nm and the minimum possible etch using standard patterning was 200nm. You can get around this with a trick called multi-patterning and double/triple patterning, which allowed us to get down to incredibly small etches. This is something that has delayed the transition to EUV (Extreme Ultra Violet) for quite a few years. EUV has a wavelength of 13.5nm and the minimum possible etch using standard patterning is just under 7nm.