Properties and performance at extremely high temperatures

Researchers from MIT, Institute of Technology Innovation, The Ohio State University, Rice University, and Bangladesh University of Engineering and Technology have published a new technical paper titled “High Temperature Stability Regrown and Alloyed Ohmic Contacts to AlGaN/GaN Heterostructure up to 500 °C.” .

Abstract
“This paper describes the stability of reclaimed and alloyed ohmic contacts with AlGaN/GaN-on-Si high electron mobility transistors (HEMT) in high-temperature applications up to 500°C. Transfer length method (TLM) measurements at temperatures from 25 to 500°C in air show that the rebuilt contacts appear to be stable up to 500°C during short-term (approximately 1 h) tests, while the alloy contacts appear to reduce contact resistance from 300 °C to 500 °C, although the increase in error limits due to the increased sheet resistance makes it difficult to draw firm conclusions. Additionally, long-term testing has shown that both technologies remain stable for at least 48 hours at 500°C, after which the large increase in sheet resistance causes the measurement uncertainty to be too large to draw definitive conclusions. Advanced microscopic images indicate that both regrown and alloyed interface areas remain structurally intact after prolonged exposure to high temperature, with no apparent degradation of crystallinity or metal composition.”

Here you will find the technical document. Published May 2024. Find the MIT press release here.

John Niroula, Qingyun Xie, Nitul S. Rajput, Patrick K. Darmawi-Iskandar, Sheikh Ifatur Rahman, Shisong Luo, Rafid Hassan Palash, Bejoy Sikder, Mengyang Yuan, Pradyot Yadav, Gillian K. Micale, Nadim Chowdhury, Yuji Zhao, Siddharth Rajan, Tomas Palacios; High temperature stability of regenerated and alloyed ohmic contacts with AlGaN/GaN heterostructure up to 500°C. Phys app Latvian. May 13, 2024; 124 (20): 202103. https://doi.org/10.1063/5.0191297.