TOKYO - Demand for next-generation power semiconductors is expected to grow as artificial intelligence servers place heavier loads on power infrastructure, raising interest in technologies once viewed mainly as a component for electric vehicles.
Power semiconductors are chips used to control motors, lighting and other equipment, as well as to convert electric power. They perform functions such as changing alternating current into direct current and adjusting voltage to supply and control electricity. Because they can withstand high voltages and large currents without breaking down, they are known as power semiconductors.
Most power semiconductors currently use silicon, the same base material as ordinary semiconductors. Silicon carbide has begun to spread in electric vehicles, but gallium nitride is now attracting attention as a higher-performance next-generation material. Silicon carbide and gallium nitride are compound semiconductors, made by combining two elements.
Power semiconductors were originally seen as a key technology for electric vehicles because they can improve electricity consumption, the EV equivalent of fuel economy in gasoline-powered cars. The sector once drew strong attention under the shift to EVs, but sentiment has weakened because of factors such as a shortage of charging stations and moves in the United States to scale back subsidies. As a result, power semiconductors have come to be viewed as one of the weaker areas in the semiconductor industry.
That view may change as demand grows from AI servers. Rapid expansion in AI hardware is putting unprecedented strain on power infrastructure. Power consumption at server racks, once measured in several kilowatts, is moving toward much higher levels, creating challenges in wiring losses and heat generation. The current 48-volt direct current power architecture is approaching its limit, making it necessary to raise supply voltage and reduce current running through wiring.
The technology attracting attention is an 800-volt direct current configuration. Nvidia has been moving ahead with this approach, which is expected to improve efficiency, increase power density and reduce the amount of copper used in wiring. Power semiconductors would be used to control the power supply in such systems.
Nvidia and Google are said to be leading the shift toward 800-volt direct current power supplies. Nvidia’s current mainstay AI semiconductor is Blackwell, while mass production of its next-generation Rubin model is expected to begin in the second half of this year. Rubin Ultra is expected to follow around the second half of next year, with Feynman projected around 2028. Power requirements for racks using Rubin Ultra and Feynman are expected to rise sharply, reaching levels far above current systems.
As 800-volt direct current systems using silicon carbide and gallium nitride move closer to adoption, demand for high-performance power semiconductors is expected to increase. Gallium nitride power semiconductors are seen as particularly important for AI data centers, where high-capacity power conversion and voltage control are required. They are also expected to be used in EVs, despite the current slowdown in that market.
Gallium nitride could significantly shorten EV charging times. Charging that takes about 90 minutes with silicon and around 20 minutes with silicon carbide could eventually be reduced to about five minutes with gallium nitride, according to the discussion. The material is expected to offer not only higher durability and output but also improved efficiency.
Research firm Fuji Keizai said in June that the global power semiconductor market is projected to reach 7.3495 trillion yen in 2035, nearly double the 2025 level. The firm said adoption is increasing for AI server power supply equipment as server rack power output rises and conversion efficiency becomes more important, adding that future growth is expected.
Several Japanese companies are being watched in connection with the market. Rohm, long associated with power semiconductors, has invested heavily in silicon carbide power semiconductors, though weaker EV demand has created difficult conditions. The company is also working on next-generation power semiconductors and is developing power devices needed for the power supply section of 800-volt direct current configurations. In June last year, Rohm announced that it would collaborate with Nvidia on the development of an 800-volt power supply architecture for next-generation AI data centers. The company has said the technology could bring major changes to future data center design and that it plans to work with data center operators.
Renesas Electronics has also moved into gallium nitride. Two years ago, it announced the acquisition of Britain’s Transphorm, a company that designs and manufactures high-performance gallium nitride products. In July last year, Renesas announced a new 650-volt gallium nitride power semiconductor product. In February this year, gallium nitride power semiconductor supplier EPC announced a comprehensive licensing agreement with Renesas, indicating that the company has been advancing its position in the field.
Toyoda Gosei is at an earlier stage. In January last year, the company said it had verified that performance of power semiconductors could be improved using high-quality gallium nitride substrate technology it developed for gallium nitride power semiconductors. The company has not yet reached full commercialization or production, but is participating in a project led by the Environment Ministry aimed at practical application.
NGK Insulators, formerly known as Nippon Gaishi, has developed a gallium nitride wafer substrate called FGan. The company has succeeded in enlarging and improving the quality of gallium nitride wafer substrates. According to the company, creating gallium nitride crystals has been extremely difficult and has posed a barrier to practical application, but NGK has succeeded in reducing crystal defects and disorder to one-tenth of previous levels, bringing the technology closer to use.
Shin-Etsu Chemical, best known for silicon wafers, is also involved in gallium nitride. The company has reportedly developed and supplied substrates for manufacturing gallium nitride semiconductors. Its system uses a proprietary QST substrate made with materials including aluminum nitride as a base on which gallium nitride layers are grown. The technology is expected to improve power control efficiency in AI data centers and contribute to lower power consumption.
Mitsubishi Chemical Group is another company drawing attention. According to a report in The Nikkei, Mitsubishi Chemical and Japan Steel Works will increase production capacity for gallium nitride used in next-generation power semiconductor substrates by 50% by 2027. The two companies have been working jointly on gallium nitride for some time, and the report said they expect demand to expand for fast EV charging, inverters and data center power supplies. The move suggests that practical application and mass production are moving closer. The report said the technology’s strengths include lower costs and fewer defects compared with conventional methods.
The market’s perception of power semiconductors could change if they become recognized as a key AI-related technology rather than a weak EV-related field. If mass production begins and profitability improves, the sector may draw renewed attention from investors, with some comparing the potential shift to earlier growth in multilayer ceramic capacitors.
Source: 日経CNBC 公式チャンネル
