![]() ![]() The remaining photoresist is then removed. The exposed photoresist is developed (removed) and the unprotected areas are etched. A blank photomask is covered with photoresist, which is then baked (solidified) in an oven, and later exposed to laser light, using maskless lithography. īlank photomasks are mainly made by two companies: AGC Inc. The multilayer may be protected by a thin ruthenium layer. The pattern is defined in a tantalum-based absorbing layer over the multilayer. An EUV mask consists of 40 alternating silicon and molybdenum layers this multilayer acts to reflect the extreme ultraviolet light through Bragg diffraction the reflectance is a strong function of incident angle and wavelength, with longer wavelengths reflecting more near normal incidence and shorter wavelengths reflecting more away from normal incidence. This is in contrast to conventional photomasks which work by blocking light using a single chromium layer on a quartz substrate. Source: ASML to ship EUV tools Masks ĮUV photomasks work by reflecting light, which is achieved by using multiple alternating layers of molybdenum and silicon. Because it is such a key technology for development in many fields, the USA even pressured ASML to not sell these machines to China. This made the once small company ASML the world leader in the production of steppers and monopolist in this cutting edge technology and resulted in a record turnover of 18.6 billion € in 2021, dwarfing their competitors Canon and Nikon. The stepper uses Zeiss lenses, which that company calls "the most precise mirrors in the world" and are produced by locating imperfections and then knocking off individual molecules. As of 2022, a stepper produces 200 wafers per hour. The first prototype in 2006 produced one wafer in 23 hours. ![]() This led MIT Technology Review to name it 'the machine that saved Moore's law'. And some even predicted the end of Moore's law.īut in 2018 Dutch company ASML finally succeeded after 2 decades of research. The then leading producers of steppers, Japanese companies Canon and Nikon gave up trying. EUV is absorbed by glass and even air, so instead of using lenses, as before, to focus the beams of light, mirrors in a vacuum would be needed and a reliable production of EUV was also problematic. ![]() The EUV technology was considered impossible by many. The next step, going even smaller, was dubbed Extreme UV or EUV. Later UV light was used, with wavelength of at first 365nm (mercury "i line"), then excimer wavelengths first of 248 nm ( krypton fluoride laser) and then 193 nm ( argon fluoride laser), which was called deep UV. In the 1960s, visible light was used for IC-production, with wavelengths as small as 435 nm (mercury "g line"). 13 Single patterning extension: anamorphic high-NA.10.1 Multilayer reflectivity random variations.8.1 Impact of photoelectron and secondary electron travel on resolution.8 EUV photoresist exposure: the role of electrons.7.2.1 Impact of slit position and aberrations.7 Enhancement opportunities for EUV patterning.6.2 Wavelength bandwidth (chromatic aberration).6.1.1 Pattern shift from defocus (non-telecentricity).5.2 Comparison to other lithography light sources.5 Light source power, throughput, and uptime.Samsung's 5 nm is lithographically the same design rule as 7 nm, with a minimum metal pitch of 36 nm. At IEDM 2020, TSMC reported their 5 nm minimum metal pitch to be reduced 30% from that of 7 nm, which was 40 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. It is widely applied in semiconductor device fabrication process.Īs of 2022, ASML Holding is the only company who produces and sells EUV systems for chip production, targeting 5 nm and 3 nm. It uses 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. Lithographic technique using an extreme ultraviolet wavelength, usually 13.5 nmĮxtreme ultraviolet lithography (also known as EUV or EUVL) is an optical lithography technology used in steppers, machines that make integrated circuits (ICs) for computers and other electronic devices. ![]()
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