I-Corps: Aluminum Nitride-based Power Transistors

这个I-Corps项目的更广泛的影响/商业潜力是扩大高频，大功率信号放大的限制。这对于未来的无线通信系统是必要的，包括第六代（6G）无线技术。6G将需要更高的工作频率来实现更快的数据传输。随着频率的增加，信号强度在更短的距离内减弱。为了抵消这个问题，还必须以更高的功率传输信号，以便能够将信号传输到必要的距离。对这种高功率、高频率组合的需求预计将继续增长，而这里开发的设备旨在实现这种性能。大功率、高频数据传输也是自动驾驶汽车面临的一个问题。高频信号可以详细、实时地绘制汽车周围环境的地图。高功率确保了信号可以穿越雨雾，在减弱到无法检测之前返回汽车。这里开发的设备可以在更远的范围内绘制更详细的地图，使自动驾驶汽车更智能、更安全。这个i-Corps项目开发氮化铝（AlN）作为氮化镓（GaN）晶体管的新平台。与传统的氮化铝平台相比，氮化铝平台的材料优势是双重的。氮化氮的电阻性比氮化氮高得多，这可以防止有害器件性能的泄漏电流。同时，AlN的导热系数比GaN大50%左右。其结果是更有效的散热，使设备在更高的功率下工作。基于氮化铝的功率晶体管的研究主要集中在晶体生长和器件制造上。优化的晶体生长可以实现高质量的AlN和GaN，提高器件性能。然后将生长的晶体加工成晶体管，这需要最先进的制造工具和精细的工艺。与最先进的氮化镓晶体管相比，AlN晶体管显示出高击穿电压，这是衡量功率性能的关键指标。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The broader impact/commercial potential of this I-Corps project is to expand the limits of high-frequency, high-power signal amplification. This will be necessary for future wireless communications systems, including sixth generation (6G) wireless technology. 6G will require higher operation frequencies to enable much faster data transmission. As frequency increases, signal strength diminishes over much shorter distances. To offset this issue, signals must also be transmitted at higher powers to be able to carry the signal the necessary distance. The demand for this combination of high-power, high-frequency is expected to continue to grow, and the devices developed here are designed to achieve such performance. High-power, high-frequency data transmission is also an issue for self-driving cars. High-frequency signals enable detailed, real time mapping of a car's surroundings. High-power ensures the signal can travel through rain and fog, and return to the car before weakening beyond detection. The devices developed here can enable more detailed mapping at a longer range to make self-driving cars smarter and safer.This i-Corps project develops aluminum nitride (AlN) as a new platform for gallium nitride (GaN) transistors. The material advantages of an aluminum nitride platform over the traditional GaN platform are two-fold. AlN is much more electrically resistive than GaN, which prevents undesired leakage currents that hurt device performance. At the same time, the thermal conductivity of AlN is approximately 50% larger than that of GaN. The result is more efficient heat dissipation, enabling device operation at higher power. The research behind AlN-based power transistors is focused on crystal growth and device fabrication. Optimized crystal growth enables high quality AlN and GaN, improving device performance. The as-grown crystal is then processed into transistors, which requires state-of-the-art fabrication tools and refined processes. The AlN transistors have demonstrated high breakdown voltages when compared to state-of-the-art GaN-based transistors, a key measure for power performance.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.