Samsung Electronics is testing S&S Tech’s (101490) domestic EUV blank masks in its 4nm foundry mass production environment. This marks the first time these masks have been introduced on an actual production line

The goal is to reduce dependence on Japan’s Hoya, strengthen supply chain resilience, and gain more pricing leverage
Samsung has reportedly been giving S&S Tech feedback to improve quality, while S&S Tech has already invested heavily in inspection equipment and a new Yongin factory to support the effort. If localization succeeds, Samsung could save tens of billions of won annually and shorten lead times, although mass production orders could still take anywhere from six months to over a year
"I understand that S&S Tech masks are being used in the EUV process, which is relatively less demanding even within the 4nm node, an industry insider said. The fact that they are testing samples on the actual mass production line shows a strong commitment to localization." The insider added that Samsung aims to reduce its dependence on Japan’s Hoya and, over time, secure greater pricing power
A blank mask is the base material for photomasks used to transfer circuit patterns onto wafers during semiconductor manufacturing. It is typically made by depositing a thin film of metal or compound onto a high-purity glass substrate. Chipmakers then engrave circuit patterns onto the blank mask to create the final photomask
EUV blank masks differ significantly from traditional deep ultraviolet, or DUV, products. DUV blank masks are transmissive, meaning ultraviolet light passes through the substrate to form patterns on the wafer. EUV blank masks, by contrast, are reflective, meaning extreme ultraviolet light is reflected rather than transmitted. They are made by alternating dozens of layers, around 40 pairs, of molybdenum and silicon on a glass substrate. Because of EUV’s short wavelength, even extremely small defects can be critical, which makes both manufacturing and inspection far more demanding
Early last year, S&S Tech invested more than 40 billion won in inspection equipment from Japan’s Lasertec for its EUV blank mask line. The equipment was reportedly installed at the new Yongin factory, which the company completed in October last year
Samsung Electronics currently imports most of its EUV blank masks from Japan’s Hoya. However, it has faced procurement issues several times in the past due to disruptions such as earthquakes in Japan. Although Hoya expanded production in Singapore to address these problems, concerns within the semiconductor industry have remained
EUV blank masks cost tens of millions of won per sheet, while high-end versions can exceed 100 million won. Samsung reportedly expects annual savings in the tens of billions of won, along with shorter lead times, if S&S Tech can successfully localize supply
"I understand that S&S Tech is now working on improvements to reduce particle generation after receiving feedback from Samsung Electronics, an industry official said. It could take anywhere from six months to more than a year before mass production orders are issued."