Over 10% of the world's electricity vanishes as heat during power conversion.

A breakthrough material called "gallium oxide" could change everything. FLOSFIA, a Kyoto University spinoff, has just achieved mass production technology for 4-inch wafers, at just 1/50th the cost of competing SiC substrates.

With manufacturing equipment costs also slashed to 1/10th, this Japanese-origin technology is positioning to disrupt the global semiconductor landscape.

What Is Gallium Oxide? The "Ultimate Material" for Power Semiconductors

Power semiconductors are essential components that convert and control electrical power. While silicon (Si) has dominated for decades, next-generation materials like silicon carbide (SiC) and gallium nitride (GaN) are gaining traction.

But gallium oxide (Ga2O3) stands apart. The "Baliga figure of merit", a key indicator of power semiconductor performance, tells the story clearly. If silicon equals 1, SiC scores around 500, and GaN reaches approximately 930. Gallium oxide? Between 3,444 and 6,726, depending on crystal structure.

This means gallium oxide could theoretically achieve far more efficient power conversion than any currently available material.

FLOSFIA's Technical Breakthrough

In December 2025, Kyoto University startup FLOSFIA announced a significant milestone.

The company completed verification of manufacturing technology for 4-inch gallium oxide (α-Ga2O3) wafers for power semiconductor devices. Additionally, prototype Schottky barrier diodes (SBDs) demonstrated substantially improved reliability.

Key achievements include:

  • 600V breakdown voltage, 10A-class devices successfully prototyped
  • Leakage current under reverse voltage reduced to less than 1/1000th of previous levels
  • Devices survived 1,500 hours of continuous reverse bias testing at 150°C

Three Reasons for the Dramatic Cost Advantage

FLOSFIA's gallium oxide technology attracts attention primarily for its overwhelming cost competitiveness.

1. Sapphire Substrate Utilization

Approximately 48% of SiC device manufacturing costs come from substrates. FLOSFIA's α-Ga2O3 devices use widely available, inexpensive sapphire substrates, reducing substrate costs by up to 50 times.

2. Proprietary "Mist Dry Method"

FLOSFIA developed "Mist Dry," an evolution of Kyoto University's "Mist CVD" technology. Raw materials are atomized and deposited onto heated substrates at temperatures below 500°C. Since SiC manufacturing requires 1,500-2,000°C, this approach cuts equipment investment to less than 1/10th.

3. Existing Factory Compatibility

The technology can utilize process equipment already installed in GaN-LED and SiC factories, significantly lowering barriers to mass production.

Applications and Market Outlook

Gallium oxide power semiconductors have diverse applications: EV power control units, data center power supplies, solar inverters, and industrial robot drive systems.

The EV market particularly benefits from gallium oxide's low power loss characteristics, potentially extending range and reducing charging times.

According to Yano Research Institute, the global wide-bandgap semiconductor crystal market is projected to reach 286.9 billion yen in 2025 and 829.8 billion yen by 2035. The overall next-generation power semiconductor market is expected to grow at approximately 20% annually, reaching around 3.5 trillion yen by 2035.

Implications for Japan's Semiconductor Industry

The SiC market currently faces intense price competition due to slowing EV demand and massive investment by Chinese manufacturers. Japanese companies maintain technological advantages but struggle with cost competitiveness.

FLOSFIA's α-Ga2O3 technology offers a potential breakthrough. The company has filed over 700 patents, creating significant barriers to entry through its "only-one technology" approach.

Major Japanese corporations have invested in FLOSFIA, including DENSO, Mitsubishi Heavy Industries, Daikin Industries, Yaskawa Electric, and JSR. The company has raised funding across multiple rounds as it works toward mass production.

Future Prospects and Challenges

FLOSFIA plans to expand its lineup from 600V to 1,200V and 1,700V breakdown voltages, with current ratings increasing from 10A to hundreds of amperes.

Challenges remain. Gallium oxide historically struggled with P-type semiconductor layer formation, but FLOSFIA developed the world's first P-type material, iridium-gallium oxide (α-(IrGa)2O3), overcoming this barrier. Sample shipments of next-generation JBS-structure SBDs are scheduled to begin in 2025.

As the world pursues carbon neutrality, improving energy efficiency is a universal priority. Whether Japanese gallium oxide technology becomes a key solution to this challenge has captured global attention.

Japan is increasingly focused on gallium oxide as the "post-SiC" material. What's happening with next-generation power semiconductor development in your country? Share your thoughts in the comments!

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