08-17-2017, 12:03 AM
Extreme ultraviolet lithography (also known as EUV or EUVL) is the next generation lithography technology using extreme ultraviolet (EUV) wavelength, currently expected to be 13.5 nm. EUV is currently being developed for possible further use in conjunction with Immersion Lithography with a resolution step 32 nm, sometimes referred to as node 7 nm. [1] Primary EUV tool manufacturer, ASML EUV projects with 5 nm node requires a higher numerical aperture than at present and multiple pattern to a greater extent than in immersion lithography 20 nm node. [2] Immersion Lithography is still more than 4 times faster than EUV (275 WPH against 65 WPH as described below), due to the power source limitations; Therefore, multiple printing with Immersion Lithography was used where EUB earlier, is expected to be used. However, it is now recognized that the EUB cannot implement 40-50 nm step, because of the random effects in the resist exposure, [3], so even 10 nm node from the limits.
While the power supply is a major problem because of its impact on productivity, significant changes in the EUV masks infrastructure, including letterheads, Filmic and inspections are also being studied. Particle pollution would be prohibitive, if the Film were not stable above 200 Watts, i.e. Trust capacity for production. [4] Without Film, Adders particles lead to reduced yields, which was not a problem for conventional optical lithography with 193 nm light and Film, the current lack of any suitable material plaque, rising when using hydrogen plasma treatment in EUV scanner, [5] [6] preclude the EUV Lithography for mass production.
Some issues not specific to EUV, such as resistance to collapse [8] and stochastic effects (including photon shot noise), [9] is also currently bar EUV from exceeding limits the resolution of Immersion Lithography in a large production volume. [10]
Double structuring is expected for EUV for random logic models on site 7 nm (32 nm main tone) Dipole due to the need of lighting. [11] Node 5 nm (22 nm main tone) [12] would also want to use multiple structuring is already being developed for Immersion Lithography.
https://str.llnl.gov/str/pdfs/11_99.1.pdf