As global semiconductor firms invest in compound semiconductors, Japan-based companies are stepping up their efforts on gallium nitride (GaN) to expand its applications beyond electric vehicles and to produce larger GaN wafers, reports Nikkei, Nikkan, and Nikkan Jidosha Shimbun.
Driven by the growing demand for electric vehicles and AI servers, Japanese companies are racing to develop larger and more efficient GaN substrates for power semiconductors. Sumitomo Chemical, Mitsubishi Chemical Group, Toyota Gosei, and Shin-Etsu Chemical are all investing in research and development to expand their production capabilities and reduce costs.
Sumitomo Chemical has established a mass production system for 2-inch and 4-inch substrates and is working towards producing 6-inch substrates for electric vehicles by 2028. Mitsubishi Chemical Group is also developing GaN substrates, aiming for significant cost reductions and increased revenue by 2030.
Shin-Etsu Chemical is advancing substrate enlargement using innovative techniques and materials such as aluminum nitride to produce substrates for GaN crystal growth, known as QST substrate technology. They have successfully developed a 12-inch diameter substrate measuring 300 millimeters and are currently developing manufacturing processes for 8-inch substrates tailored for vertical configurations.
Meanwhile, Toyota Gosei, a Japanese automotive supplier, is expanding its production of GaN substrates for power semiconductors. The company is investing in new growth furnaces at its Aichi Prefecture factory to increase seed crystal production capacity tenfold by March 2025. These seed crystals are essential for growing larger GaN wafers, which are used in power semiconductors for electric vehicles and other applications.
In collaboration with Osaka University and Mitsubishi Chemical, Toyota Gosei is also developing technology to produce GaN wafers larger than 6 inches. This technology is based on high-quality crystal growth techniques developed over the past decade. The company plans to invest in large-scale production lines to meet the growing demand for GaN substrates.
Toshiba Group is set to enter the GaN power semiconductor market in 2024, aiming to commercialize a "Normally Off" type by 2026. The company's first GaN power device is expected to have a breakdown voltage of 650V and a conduction resistance of 35 milliohms.
Toshiba's product features a unique combination of its proprietary Normally On device with a cascode structure, which allows for external gate resistance control and reduces the likelihood of erroneous operations. This technology is designed to meet the growing demand for high-performance power semiconductors in the AI server market.
Article translated by Jingyue Hsiao
