U.S. DARPA responds to China’s gallium export controls: awards Raytheon three-year contract to develop new types of transistors

Advanced power chips and radio frequency amplifiers rely on wide-bandgap (WBG) semiconductor materials like gallium nitride (GaN). China controls the lion’s share of gallium supply and its recent export restriction on gallium potentially mean additional risks for American national security. To respond to this challenge, the U.S. Department of Defense agency DARPA (Defense Advanced Research Agency) has tasked Raytheon to develop synthetic diamond and aluminum nitride semiconductors. 

Raytheon’s objective is to lead the advancement of these materials into devices optimized for both current and next-generation radar and communication systems, such as radio frequency switches, limiters, and power amplifiers enhancing their capabilities and range. This includes applications in cooperative sensing, electronic warfare, directed energy, and integration into high-speed weapon systems like hypersonics. 

With its 3.4 eV bandgap, GaN is already a leading material in high-power and high-frequency semiconductors. Synthetic diamond has the potential to surpass GaN’s capabilities (with its bandgap of around 5.5 eV) in applications where high-frequency performance, high electron mobility, extreme thermal management, higher power handling, and durability are critical. However, synthetic diamond is an emerging material for semiconductors and there are still challenges associated with its mass production. Aluminum nitride (AlN) has an even wider bandgap of about 6.2 eV, making it even better for the aforementioned applications. Raytheon has yet to develop appropriate semiconductors. 

In the first phase of the contract, Raytheon’s Advanced Technology team will focus on developing semiconductor films based on diamond and aluminum nitride. The second phase will focus on refining and advancing the diamond and aluminum nitride technology for use on larger diameter wafers, specifically targeting sensor applications. 

Under the terms of the contract, Raytheon must complete both phases in three years, which highlights urgency of the project. Raytheon already has plenty of experience in integrating GaN and GaAs into radar applications, so it seems that DARPA has turned to the right company. 

“This is a significant step forward that will once again revolutionize semiconductor technology,” said Colin Whelan, president of Advanced Technology at Raytheon. “Raytheon has extensive proven experience developing similar materials such as Gallium Arsenide and Gallium Nitride for Department of Defense systems. By combining that pioneering history and our expertise in advanced microelectronics, we’ll work to mature these materials towards future applications.”