Demonstration of N-Polar All-AlGaN High Electron Mobility Transistors With 375 mA/mm Drive Current

• Published in: IEEE electron device letters Vol. 44; no. 7; pp. 1072 - 1075
• Main Authors: Noshin, Maliha, Soman, Rohith, Chowdhury, Srabanti
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.07.2023; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: AlGaN; HEMTs; high electron mobility transistor; High electron mobility transistors; III-V semiconductor materials; Logic gates; MODFETs; nitrogen polar; Performance evaluation; Semiconductor devices; ultrawide bandgap material; Voltage measurement; Wide band gap semiconductors
• ISSN: 0741-3106; 1558-0563
• DOI: 10.1109/LED.2023.3279400

Devices made from ultrawide bandgap (UWBG) materials are being widely investigated for high-power and radio frequency (RF) electronics. High electron mobility transistor (HEMT) is one of the most effective designs to implement heterostructures in III-Nitrides and III-Oxides that leverage a 2D-channel with high conductivity and large breakdown electric field. Nitrogen (N)-polarity in GaN channel HEMTs have shown remarkable performance advantage in both power and RF applications compared to its metal-polar counterpart. Here, UWBG N-polar AlGaN channel HEMT can bring further performance benefits due to an increase in the channel's breakdown electric field. In this work, we report the first experimental demonstration of N-polar all-AlGaN HEMT devices with two different Al compositions (20% and 30%) in the channel. The HEMT with 3 <inline-formula> <tex-math notation="LaTeX">\mu \text{m} </tex-math></inline-formula> long-channel (20% Al) showed a drive current of 375 mA/mm (at 0 V gate voltage). These devices also show low on-state leakage current of ~0.5 nA/mm, and large on/off ratio of <inline-formula> <tex-math notation="LaTeX">\sim 2\times 10^{{8}} </tex-math></inline-formula>. Furthermore, > 400 V breakdown voltage was achieved without any field plate structures.