Samsung Electronics recently unveiled the current status and prospects of its extreme ultraviolet (EUV) exposure process, generating significant interest globally. Particularly noteworthy is Samsung's dependence on Japanese suppliers for pellicles, with a transmittance rate of around 90%, as the company has yet to transition to domestically produced alternatives in South Korea.
At the 2023 Korean International Semiconductor Conference on Manufacturing Technology (KISM 2023) held recently in Busan, researcher Kang Yong-seok from Samsung's Device Solutions (DS) Division highlighted the status and future trajectory of Samsung's EUV technology applications. The focus was on the application of pellicles, identified as a key aspect of the company's technological advancements.
Kang disclosed that as of the third quarter of 2023, Samsung's EUV pellicles achieved a transmittance rate of 90%, with a target to enhance it to 94-96%.
Notably, pellicles are mainly used in the lithography process to protect photomasks from micro-dust contamination, preventing particles and foreign objects from being etched onto wafers. However, pellicles must also have a sufficient transmittance rate to ensure the yield of the lithography process.
In other words, an EUV pellicle with a transmittance rate of 90% may impact the reproduction of ideal circuit patterns. Compared to deep ultraviolet (DUV) pellicles with argon fluoride (ArF) process boasting a 99.3% transmittance, EUV pellicles face challenges in achieving similar effectiveness.
Apart from transmittance, the quality of EUV pellicles is crucial to prevent bending or cracking during the exposure process, adding complexity to commercialization efforts.
According to media reports, Samsung has already introduced EUV pellicles in some of its EUV wafer foundry lines, primarily serving major customers. However, the company still believes it can mass-produce memory using EUV processes even without pellicles in certain situations, considering factors like production efficiency and cost.
Currently, Samsung relies solely on Mitsui Chemicals of Japan for its EUV pellicle needs. While South Korean companies like S&S Tech and FST are actively developing their own alternatives, they have not yet entered mass production.
Samsung, in collaboration with these domestic companies, has successfully developed EUV pellicles with an 88% transmittance. As advanced processes evolve, the need for high-performance EUV pellicles will only grow, making the choice of Samsung's first local partner highly anticipated by the industry.
Article translated by Willis Ke
