Gallium nitride (GaN) is already used in power devices for consumer electronics, but manufacturers are now developing the technology for use in the automotive sector, with the compound set to make its way into vehicles in the coming year.
GaN semiconductors are currently used in consumer and industrial applications, including alternating current adapters and server power supply units. But use of GaN semiconductors in automotive applications is at an early stage — unlike silicon carbide (SiC) chips, which are increasingly being incorporated into electric vehicle (EV) power electronics.
GaN has a similar crystalline structure to silicon but can deliver greater efficiency, faster switching speeds and higher thermal conductivity. Lower resistance, smaller form factors and the ability to operate at higher voltages mean GaN semiconductors consume less power than silicon semiconductors.
Integrating GaN into silicon substrates rather than sapphire is opening up new uses for GaN in vehicle power devices and light detection and ranging (LiDAR). GaN is suitable for low and high-voltage applications for EVs, including on-board chargers (OBCs), power inverters and traction motors.
US-based semiconductor firms Navitas Semiconductor and Texas Instruments (TI), and Chinese-owned Nexperia have been developing GaN chips for automotive for several years and are now moving quickly into higher voltages. Several manufacturers have now started producing devices and expect to gain traction over the next year.
Navitas has been producing GaN devices since 2018 and expects to begin making the product for the automotive industry in 2025.
Japan's ROHM Semiconductor in December partnered with the world's largest semiconductor company, Taiwan-based TSMC, to develop and produce GaN power devices for EVs. The companies will integrate ROHM's device development technology with TSMC's GaN-on-Si process technology and provide control integrated circuits to maximise performance.
Israeli firm VisIC Technologies is developing GaN products for automotive and industrial uses. It announced plans in December to partner with Austrian automotive technology developer AVL to advance inverter technology for EVs. The firms aim to produce devices that offer higher performance and lower costs at both the device and system level, compared with SiC devices. VisIC's GaN-on-silicon power devices consume less energy during production and can be manufactured in 200mm and 300mm silicon foundries to scale up output.
VisIC plans to work with AVL to expand the platform to include 800V power modules — the next generation of EV charging technology.
China's Innoscience Technology is developing GaN-on-Si power products and recently launched two 100V automotive-grade devices optimised for LiDAR for advanced driver assistance and autonomous driving applications, as well as DC-DC converters and automotive audio applications. The company has started mass production and is fulfilling batch orders to meet demand.
Several manufacturers and foundries are now building out capacity to accommodate commercial-scale output of GaN devices.
US-based GlobalFoundries said in early December it has received $9.5mn in federal funding to continue adding new tools, equipment and prototyping capabilities at its Vermont facility, as it moves closer to full-scale manufacturing of its 200mm GaN-on-Si chips.
And TI started producing GaN-based power semiconductors at its factory in Aizu, Japan, in October. As the site ramps up, TI's internal capacity will quadruple between its US and Japanese factories. The company has also piloted manufacturing 300mm wafers to increase volumes.
Limitations in manufacturing have so far hampered the widespread adoption of GaN in EVs. Cost, supply-chain issues and concerns around thermal management and voltage spikes remain hurdles that manufacturers must overcome.
The technology has yet to be proven for automotive applications, which have stringent standards for quality and safety. For this reason, manufacturers are starting with GaN in OBCs and converters to establish confidence.
Companies such as Germany's Infineon and Swiss chipmaker STMicroelectronics anticipate there will be room for both SiC and GaN in the automotive sector, depending on the power, efficiency and cost requirements of the application. The availability of gallium compared with silicon may also become a factor as demand increases, given export restrictions out of primary supplier China.
