Effective Reduction of Current Collapse in AlGaN/GaN MISHEMT via Low-Temperature Nitriding Treatment

• Published in: IEEE transactions on electron devices Vol. 72; no. 4; pp. 2090 - 2094
• Main Authors: Chou, Sheng-Yao, Chen, Yan-Chieh, Lin, Cheng-Hsien, Chen, Yan-Lin, Wu, Shuo-Bin, Chen, Hsin-Chu, Chang, Ting-Chang
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.04.2025; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Aluminum gallium nitride; Aluminum gallium nitrides; Aluminum oxide; Al₂O₃/GaN interface; Annealing; Collapse; Conduction bands; Current leakage; Driving conditions; Gallium nitrides; HEMTs; high-electron mobility transistors; Hopping conduction; Leakage current; Logic gates; Low temperature; Nitrogen; normally-on AlGaN/GaN; Performance evaluation; Photoelectrons; Plasma temperature; Plasmas; reduced current collapse; Spectrum analysis; supercritical fluid (SCF) treatment; Supercritical fluids; Surface treatment; Transconductance; Wide band gap semiconductors; X ray photoelectron spectroscopy
• ISSN: 0018-9383; 1557-9646
• DOI: 10.1109/TED.2025.3542010

We successfully demonstrated a 72% reduction in current collapse under high-field driving conditions (<inline-formula> <tex-math notation="LaTeX">{V}_{\text {D}} =300 </tex-math></inline-formula> V) for AlGaN/GaN MISHEMT using low-temperature supercritical fluid nitridation (SCFN) treatment at <inline-formula> <tex-math notation="LaTeX">180~^{\circ } </tex-math></inline-formula>C for 1 h. A significant improvement in the off-state (<inline-formula> <tex-math notation="LaTeX">{V}_{\text {G}}= -10 </tex-math></inline-formula> V) gate leakage current was observed in MISHEMT with SCFN treatment, resulting in a high breakdown voltage (BV) capability of up to <inline-formula> <tex-math notation="LaTeX">{V}_{\text {D}}=710 </tex-math></inline-formula> V (at <inline-formula> <tex-math notation="LaTeX">1~\mu </tex-math></inline-formula>A/mm), compared to only <inline-formula> <tex-math notation="LaTeX">{V}_{\text {D}}=110 </tex-math></inline-formula> V without SCFN. Furthermore, in terms of characteristics, the device was improved with a 4.6% increase in maximum drain current (<inline-formula> <tex-math notation="LaTeX">{I}_{\text {D},\max } </tex-math></inline-formula>), a 2.9% increase in maximum transconductance (<inline-formula> <tex-math notation="LaTeX">{G}_{\text {m},\max } </tex-math></inline-formula>), and an 11.1% decrease in drain-source on resistance [<inline-formula> <tex-math notation="LaTeX">{R}_{\text {DS}} </tex-math></inline-formula>(on)]. These improvements can be attributed to the repairs of dangling bonds on the AlGaN surface and the elimination of the Al2O3/AlGaN interface traps, which collectively lead to improved performance and stability. Based on the abovementioned results, the X-ray photoelectron spectroscopy (XPS), conduction band edge of defect state density (<inline-formula> <tex-math notation="LaTeX">{D}_{\text {it}} </tex-math></inline-formula>), and gate leakage trap-related hopping conduction mechanism were analyzed to explain the phenomenon.