On April 2, 2026, Japan's NEDO (New Energy and Industrial Technology Development Organization) announced that Rohm had achieved the technical targets for its "8-inch Next-Generation SiC MOSFET Development" project two years ahead of the original end-of-2027 deadline. The targets were twofold: cutting power loss in converters by 50% or more, and lowering cost. Rohm met both, and the R&D project closed out in fiscal 2025.

In plain terms: Rohm has stood up a production line that makes next-generation power chips on larger wafers, chips that waste 50% less energy than conventional silicon-based alternatives.

Power semiconductors are the unsung heroes of modern electronics. They control and convert electrical power in everything from EV motor inverters and solar panel power conditioners to data center power supplies. Traditionally, silicon-based IGBTs (Insulated Gate Bipolar Transistors) have dominated this space. But SiC (silicon carbide) MOSFETs can achieve efficiency levels that silicon simply cannot match.

A concrete example: replacing silicon IGBTs with SiC MOSFETs in an EV's inverter can extend driving range by 5 to 10% on the same battery pack. Or automakers can hold the same range with a smaller, lighter, cheaper battery.

Why 8-Inch Wafers Are a Big Deal

The other crucial achievement is manufacturing SiC devices on 8-inch (200mm) wafers.

A wafer is the circular disc from which individual chips are cut. Most SiC power semiconductors today are made on 6-inch (150mm) wafers. Moving to 8-inch increases the number of chips per wafer by roughly 1.8 times, which translates directly into lower cost per chip: up to a 40% reduction by industry estimates.

But SiC is notoriously difficult to work with. Growing SiC crystals requires temperatures around 2,500°C (4,500°F), and keeping crystal defects under control while scaling up wafer size demands extremely advanced process technology. Rohm developed optimized epitaxial growth techniques (a method for growing high-quality thin crystal films on a substrate) and built a dedicated 8-inch SiC device manufacturing line at its Chikugo factory in Fukuoka Prefecture.

The NEDO-funded project began in April 2022 and originally aimed to hit its technical targets by the end of 2027. NEDO says the early finish came from deliberately front-loading the work, on the view that competitive SiC technology had to be locked down early as global demand expands.

The Global SiC Power Semiconductor Race

The SiC power semiconductor market is booming. Mordor Intelligence estimates it at roughly $2.7 billion in 2025, reaching $8.4 billion by 2030, growing at over 25% annually.

The world's major players are locked in fierce competition:

STMicroelectronics (Switzerland/France/Italy) held the top spot with approximately 33% SiC device market share as of 2023, anchored by a long-term supply deal with Tesla. It's building a fully integrated SiC fab in Catania, Italy, targeting operations by 2026.

onsemi (USA) has risen rapidly, driven by its automotive EliteSiC series. The company is transitioning to 8-inch production at its Bucheon, South Korea plant and constructing a $2 billion vertically integrated SiC facility in the Czech Republic.

Infineon Technologies (Germany) is the world's largest power semiconductor company overall. It's building a 200mm SiC mega-fab in Kulim, Malaysia, and aiming for 30% SiC market share by 2030.

Meanwhile, Wolfspeed (USA), once the pioneer of SiC technology, has faced severe headwinds. Its aggressive 8-inch wafer factory expansion racked up massive debt while production yields, according to press reports, stayed well short of the roughly 70% considered an industry benchmark. Wolfspeed filed for Chapter 11 bankruptcy in June 2025 and emerged in September with about 70% less debt. Japan's Renesas Electronics converted its Wolfspeed debt into equity and gained a board seat, reshaping the SiC competitive landscape.

Chinese competitors are also surging. Wafer suppliers TanKeBlue and SICC have rapidly expanded market share and are developing 12-inch substrates, threatening established players with aggressive pricing.

Japan's Power Semiconductor "Big Reshuffle"

Rohm's technical achievement cannot be separated from the massive industry consolidation now underway in Japan.

On March 27, 2026, Rohm, Toshiba, and Mitsubishi Electric announced they would begin talks on merging their power semiconductor businesses. In scope: Rohm itself, the semiconductor business of Toshiba subsidiary Toshiba Device & Storage, and Mitsubishi Electric's power device business. Rohm brings automotive SiC, Toshiba Device & Storage contributes silicon MOSFET expertise, and Mitsubishi Electric offers strength in IGBTs and power modules. On a simple sum, the combined entity would hold roughly 10% of the global market, second only to Infineon.

What set this off was Denso's February 2026 approach to Rohm. Denso, the core parts supplier of the Toyota Group, proposed an acquisition reported at around $8 billion. It wanted stable access to automotive-grade power chips, but folding Rohm into one automaker's supply chain raised the prospect of constrained supply to everyone else. A special committee of Rohm outside directors reviewed the offer, did not endorse it, and Denso subsequently withdrew the proposal.

Rohm CEO Katsumi Azuma said that sustainable growth requires companies with the same ambitions to come together rather than operate as small individual players. Of the Denso approach, he said it was not quite the arrival of the black ships, but that it accelerated the merger discussion.

What This Achievement Means

Standing up an 8-inch line is a step toward bringing SiC device pricing in line with silicon. Cost is the gating factor for SiC adoption, so this opens the door to mid-range EVs and industrial equipment that previously passed on it. That Japan got there while Wolfspeed struggled with the same transition is not a small detail.

Improved power conversion efficiency cuts CO2 emissions across EVs, solar, wind, and data centers alike. It's also worth noting where this came from: NEDO's Green Innovation Fund, a public-private framework, which makes the result a data point on whether that kind of industrial policy works.

How are power semiconductor development and industry restructuring progressing in your country?

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