Micron Breaks Ground on $9.3 Billion Hiroshima Fab Expansion
Alina Collins
Micron Technology broke ground on July 5 on a $9.3 billion expansion of its Hiroshima fab to produce AI high-bandwidth memory, backed by up to ¥500 billion in Japanese government subsidies — one of the largest single investments yet in the global AI memory capacity race.
What is being built, and at what cost?
The Hiroshima fab will produce high-bandwidth memory (HBM) — ultra-fast memory designed to sit next to AI processors and shuttle data far faster than standard RAM — with first shipments targeted for summer 2028.
Total investment: ¥1.5 trillion (roughly $9.3 billion). Japan's Ministry of Economy, Trade and Industry has earmarked up to ¥500 billion in subsidies. This means → Tokyo is covering about a third of the build cost.
Japan's cumulative support for Micron now stands at roughly ¥775 billion, spanning R&D and production. In plain terms = Japan is spending real money to keep advanced memory manufacturing on home soil.
Why Hiroshima?
CEO Sanjay Mehrotra said at the ceremony: "Micron's very first HBM production wafer was born right here in Hiroshima." The fab is the origin point of Micron's HBM strategy.
About 80% of the fab's chip materials are sourced domestically in Japan — a short, fast supply chain. This means → turnaround from raw material to finished product is much quicker than with overseas sourcing, enabling faster delivery of cutting-edge chips.
Micron acquired the fab in 2013 after buying bankrupt Elpida Memory, once Japan's largest DRAM maker. The expansion will improve power and data-transfer efficiency for AI workloads and autonomous driving.
Where else is Micron expanding?
Boise, Idaho: two advanced wafer fabs under construction.
Near Syracuse, New York: groundbreaking held in January for a $100 billion production campus to expand domestic DRAM (dynamic random-access memory — the most common memory type in computers and phones) capacity.
This reflects a parallel "Made in America + Made in Japan" buildout, both lines aimed at the explosion in AI-driven memory demand.
Where does Japan's semiconductor push stand?
Since 2021, Japan has allocated tens of billions of dollars to semiconductors and AI, designating the sector a core national-security priority.
Prime Minister Sanae Takaichi released a roadmap last month targeting ¥101.6 trillion in combined public and private chip-and-AI investment by March 2041 — though the government's own share was not disclosed.
Whether the Hiroshima fab delivers HBM at volume on schedule in summer 2028 will be a key test of how fast this global AI memory capacity race actually lands. In plain terms = the money is committed; what matters now is who ships product first.
Content is for reference only, not financial advice.