Xie, Qingyun, Niroula, John, Rajput, Nitul S., Yuan, Mengyang, Luo, Shisong, Fu, Kai, Isamotu, Mohamed Fadil, Palash, Rafid Hassan, Sikder, Bejoy, Eisner, Savannah R., Surdi, Harshad, Belanger, Aidan J., Darmawi-Iskandar, Patrick K., Aksamija, Zlatan, Nemanich, Robert J., Goodnick, Stephen M., Senesky, Debbie G., Hunter, Gary W., Chowdhury, Nadim, Zhao, Yuji, Palacios, Tomás, Xie, Qingyun, Niroula, John, Rajput, Nitul S., Yuan, Mengyang, Luo, Shisong, Fu, Kai, Isamotu, Mohamed Fadil, Palash, Rafid Hassan, Sikder, Bejoy, Eisner, Savannah R., Surdi, Harshad, Belanger, Aidan J., Darmawi-Iskandar, Patrick K., Aksamija, Zlatan, Nemanich, Robert J., Goodnick, Stephen M., Senesky, Debbie G., Hunter, Gary W., Chowdhury, Nadim, Zhao, Yuji, and Palacios, Tomás
This Letter reports the device and material investigations of enhancement-mode p-GaN-gate AlGaN/GaN high electron mobility transistors (HEMTs) for Venus exploration and other harsh environment applications. The GaN transistor in this work was subjected to prolonged exposure (11 days) in a simulated Venus environment (460 °C, 94 bar, complete chemical environment including CO2/N2/SO2). The mechanisms affecting the transistor performance and structural integrity in harsh environment were analyzed using a variety of experimental, simulation, and modeling techniques, including in situ electrical measurement (e.g., burn-in) and advanced microscopy (e.g., structural deformation). Through transistor, Transmission Line Method (TLM), and Hall-effect measurements vs temperature, it is revealed that the mobility decrease is the primary cause of reduction of on-state performance of this GaN transistor at high temperature. Material analysis of the device under test (DUT) confirmed the absence of foreign elements from the Venus atmosphere. No inter-diffusion of the elements (including the gate metal) was observed. The insights of this work are broadly applicable to the future design, fabrication, and deployment of robust III-N devices for harsh environment operation., Department of Defense (DoD), Department of Energy (DOE), National Aeronautics and Space Administration (NASA), Lockheed Martin Corporation; Samsung Electronics Co., Ltd.; Semiconductor Research Corporation; Bangladesh University of Engineering and Technology