Japanese semiconductor materials giant TOK is expanding its production footprint in Koriyama, Fukushima Prefecture, to strengthen its position in the global semiconductor materials market, particularly photoresists. The company announced on October 8 that a new facility at its Koriyama plant had been completed and that it plans to expand the site further.
According to Japanese financial media outlet Japan Interview News, construction of the new semiconductor photoresist building began in July 2024. The facility, one of the world's largest photoresist manufacturing buildings, represents an investment of JPY23 billion (about US$145 million) and was completed on October 8, 2026.
The building is one of the world's largest photoresist manufacturing facilities. It is scheduled to begin operations in November and will introduce automated and digitalized processes to produce semiconductor materials, including extreme ultraviolet (EUV) and argon fluoride (ArF) photoresists.
Nikkei Asia reported that products from the new facility will typically require in-house inspections and customer testing. Operations are expected to begin in November 2026, with full-scale mass production targeted for around summer 2027.
The facility was completed about six months ahead of schedule. In addition to an inspection facility completed at the Koriyama site in 2022, which shortened the testing process, strong demand for AI semiconductors contributed to the accelerated construction schedule.
Citing TOK, Nikkei Asia reported that demand for servers used in AI data centers had exceeded expectations. TOK raised its 2026 operating profit forecast by 16% to JPY60.6 billion.
Industry peers including Shin-Etsu Chemical are also actively investing to expand advanced photoresist production, highlighting the factors behind TOK's accelerated construction of the new facility.
Following completion of the new building at the Koriyama plant, TOK will need to invest further to expand production. However, limited land remains available at the site.
As a result, TOK signed a land purchase agreement with the Koriyama municipal government on March 25, 2026. The agreement gives the company approximately 9.08 hectares in Koriyama's Western No. 1 Industrial Park as a land reserve for future business development.
Article edited by Ysi Chen
