Micron breaks ground on $9.3B Hiroshima HBM fab expansion; Japan subsidizes $3.2B

Micron Technology broke ground on July 4, 2026 on a ¥1.5 trillion ($9.3 billion) expansion of its Hiroshima Prefecture factory in western Japan to produce high-bandwidth memory (HBM) and next-generation DRAM. Japan's Ministry of Economy, Trade and Industry (METI) is providing up to ¥500 billion (~$3.2 billion) in subsidies, covering roughly one-third of the capital cost, plus an additional ¥36 billion ($230 million) over five years for R&D—bringing total government support for the Hiroshima site to ¥774.5 billion (~$5 billion).

Commercial shipments from the expanded facility are targeted for the summer of 2028. The project will expand cleanroom space and manufacturing capacity for HBM4E and future generations, positioning Micron to challenge SK Hynix's 57% HBM market share and Samsung's 22%, with Micron currently at 21%. The timing reflects sustained HBM shortage: Micron's entire 2026 output is already sold out under multi-year contracts, and the company's fiscal Q3 data-center revenue reached $25 billion (more than its total revenue a year earlier).

For practitioners, Japan's $3.2 billion subsidy signals geopolitical commitment to breaking South Korea's HBM monopoly; the factory also represents Micron's first major Hiroshima expansion since 2019. The 2028 ramp assumes AI infrastructure capex remains sustained—a two-year bet in an industry where timeline slippage is common. Watch whether Micron actually allocates new HBM output to new customers or reallocates from existing DRAM to chase higher margins.