In recent years, the demand for advanced semiconductors, particularly those used in electric vehicles (EVs), has surged as the world shifts towards sustainable energy solutions. Japanese companies, renowned for their technological prowess, are at the forefront of this movement, specifically focusing on the innovation of semiconductor substrates that are larger and more cost-effective. This push is not just about enhancing performance but also about redefining the semiconductor landscape. As the automotive industry seeks to improve battery efficiency and extend vehicle range, key materials like Gallium Nitride (GaN) and Silicon Carbide (SiC) are coming under the spotlight.
Gallium nitride semiconductors are emerging as a game-changer for EVs because of their high efficiency and low energy loss compared to traditional silicon-based semiconductors. The benefits of GaN technology are noteworthy; for instance, it significantly reduces the charging time of electric vehicles. Estimates suggest that while silicon semiconductors may take around 90 minutes to charge, SiC can reduce this time to approximately 20 minutes. GaN, however, can bring this down to an impressive 5 minutes. As such, this technology is key to tackling one of the biggest challenges in EVs—charging duration.
However, despite the remarkable advantages that GaN offers, the current market is still largely dominated by SiC due to its lower production costs and existing applications in EV technologies. Industry leaders in Japan, such as Sumitomo Chemical, are racing against clock to innovate and bring GaN semiconductors into widespread use, especially targeting the automotive sector. The company is currently working on the large-scale production of GaN substrates, targeting diameters of 150mm, which is essential for automotive applications.
The size of GaN substrates is crucial because larger substrates allow for more efficient production of semiconductors, which in turn can significantly lower costs. By growing GaN crystals on a substrate, manufacturers can engage in mass production of high-quality semiconductors, thereby maximizing their output while minimizing expenses. Sumitomo Chemical is actively developing 50mm and 100mm substrates and is planning evaluations of 150mm samples by the end of the year, with aspirations to achieve mass production by 2028.
Mitsubishi Chemical is also pursuing aggressive cost-reduction strategies. The company aims to cut manufacturing expenses down to a tenth of current levels by employing innovative large-scale equipment that can streamline production. They project an operational revenue target of 10 billion yen in the power semiconductor sector by 2030. This level of ambition reflects a broader strategy of Japan’s manufacturers as they try to maintain a competitive edge in a rapidly evolving industry.
Within the semiconductor industry, GaN devices can be categorized based on the flow of current—primarily into lateral and vertical types. Currently, the more common structure used in EV applications is the lateral design, developed atop silicon substrates. However, these types face difficulties in meeting the demands for high current and voltage within EVs. Japanese companies are therefore targeting the vertical semiconductor arena, seeking to establish dominance over its development and production.
Toyota Tsusho is pioneering efforts from seed crystal development to substrate manufacturing and solid-state circuit component integration, further positioning themselves strategically within the market. They are ramping up crystal growth capabilities at their Aichi-based facility, with plans to increase seed crystal production by tenfold by March 2025.
Collaboration is essential as organizations like Toyota Tsusho team up with other giants like Mitsubishi Chemical to streamline the transition from seed crystals to substrates. By employing a cohesive system, they believe they can optimize development efficiency and quickly overcome material challenges that may arise.
In an innovative twist, Shin-Etsu Chemical has taken a different approach by using aluminum nitride (AlN) substrates instead of GaN, aiming to create GaN crystals on these bases. As of September, they achieved success in developing a 300mm substrate, with an eye on both lateral and vertically structured manufacturing technologies.
Processors will also need to refine substrate processing techniques, including grinding and polishing, as GaN's hardness requires significantly more time to prepare than SiC. This indicates the need for a holistic approach to cost-cutting throughout every production phase.
The global market for GaN is projected to explode, with estimates suggesting that by 2030, the GaN solid-state circuit component market could exceed $2.3 billion—an increase that reflects growing recognition of GaN's unique properties over traditional materials. As companies increasingly prioritize performance, GaN’s ability to operate effectively over smaller areas comes into play, making it an attractive option even at a higher price point.
As Japan faces competition from Chinese and other global players in the GaN semiconductor sector, it is imperative that Japanese enterprises leverage their advanced technologies to break into the promising EV market. Here lies the pivotal question: Can Japanese companies maintain their competitive edge globally? Success hinges on their ability to innovate in the production of large and high-quality GaN substrates and to deliver effective solutions to automotive manufacturers. The race is on, and the stakes are as high as ever.