Trapping Effects on Leakage and Current Collapse in AlGaN/GaN HEMTs

• Published in: Journal of electronic materials Vol. 49; no. 10; pp. 5687 - 5697
• Main Authors: Sharma, Niketa, Periasamy, C., Chaturvedi, Nitin, Chaturvedi, Nidhi
• Format: Journal Article
• Language: English
• Published: New York Springer US 01-10-2020; Springer Nature B.V
• Subjects: Aluminum gallium nitrides; Barrier layers; Buffer layers; Characterization and Evaluation of Materials; Chemistry and Materials Science; Density; Electronics and Microelectronics; Energy levels; Gallium nitrides; High electron mobility transistors; Instrumentation; Leakage current; Materials Science; Optical and Electronic Materials; Semiconductor devices; Solid State Physics; Trapping; Current collapse; traps; drain current; transconductance; GaN HEMTs
• ISSN: 0361-5235; 1543-186X
• DOI: 10.1007/s11664-020-08299-0

In this paper, we showcase our investigation regarding the effect of acceptor traps in GaN buffer and AlGaN barrier layers on the leakage current and current collapse in GaN high-electron-mobility transistors. The dependence of current collapse and leakage current on the density and energy level of traps is carefully considered. With an increase in trapping density from 10
15
 cm
−3
to 10
18
 cm
−3
, the leakage current was significantly reduced from 80.2% to 1.76% in the buffer layer and 95% to 12.6% in the barrier layer, while the current collapse increased from 6% to 89.8% in the buffer layer and 0.3% to 17.5% in the barrier layer. The effects of current collapse and leakage were more noticeable in the buffer layer than in the barrier layer. Different energy levels (0.75 eV, 1.8 eV, and 2.85 eV) of acceptor traps were likewise studied. It was demonstrated that high-energy traps induced a lower amount of leakage, while the current collapse was greater. Based on these results, a balanced trade-off between the current collapse and the leakage current is proposed.