Semiconductor History | 吉川工業団地, 東広島 — Japan's Last DRAM Line, and the Water That Makes the Sake

The plant sits on a rise above a gravel lot at the edge of an industrial estate in 東広島市, and in a photograph taken in January 2009 the word ELPIDA is on both of the long buildings. Elpida did not build it. 広島日本電気 was incorporated in September 1988 and opened the fab at 吉川工業団地 in 1989, as an NEC subsidiary. When NEC and 日立製作所 merged their memory businesses in 1999, the site and the people on it went across to the new venture. A production company, 広島エルピーダメモリ, took the plant over in 2003 and was absorbed back into the parent in 2008. In 2013 the whole thing became American. Three owners, one site, and it has never stopped making DRAM. It is the only plant in Japan that still does. 西条, in the same city, is one of Japan's better-known sake districts, and its brewers work with soft water. A DRAM fab needs water too, ultrapure and in quantities most places cannot supply. Micron's chief executive drew those two facts together out loud at the groundbreaking in July 2026, invoking 三浦仙三郎, the 東広島 brewer who spent decades working out how to make good sake from soft water instead of accepting that it could not be done. The current numbers are not small. The site covers 302,000 square metres and runs around 40,000 300-millimetre wafers a month. HBM4 built on the 1γ node is already in volume production here, patterned with EUV, which the plant's management says is the first EUV mass production anywhere in Japan. On 4 July 2026 the company broke ground on a new cleanroom, the first phase about 28,000 square metres, with equipment due to move in during late 2028. The declared cost is ¥1.5 trillion. The Ministry of Economy, Trade and Industry is putting in ¥500 billion of that plus ¥53 billion for research, and in exchange domestic customers get priority when supply is tight. A company that Idaho investors funded in 1978 now operates Japan's only DRAM fab, on Japanese public money, in a plant NEC built. This is an operating factory. Look at it from the public road and leave the gates alone. The photograph is the plant in January 2009, three years before Elpida's collapse, with the company name still on both buildings. Photo: OS6, CC BY-SA 3.0, via Wikimedia Commons