Investigation of trap states in high Al content AlGaN/GaN high electron mobility transistors by frequency dependent capacitance and conductance analysis
Jie-Jie Zhu,
Xiao-Hua Ma,
Bin Hou,
Wei-Wei Chen,
Yue Hao
Affiliations
Jie-Jie Zhu
State Key Discipline Laboratory of Wide Bandgap Semiconductor Technology, School of Advanced Materials and Nanotechnology, Xidian University, Xi'an 710071, People's Republic of China
Xiao-Hua Ma
State Key Discipline Laboratory of Wide Bandgap Semiconductor Technology, School of Advanced Materials and Nanotechnology, Xidian University, Xi'an 710071, People's Republic of China
Bin Hou
State Key Discipline Laboratory of Wide Bandgap Semiconductor Technology, School of Advanced Materials and Nanotechnology, Xidian University, Xi'an 710071, People's Republic of China
Wei-Wei Chen
State Key Discipline Laboratory of Wide Bandgap Semiconductor Technology, School of Advanced Materials and Nanotechnology, Xidian University, Xi'an 710071, People's Republic of China
Yue Hao
State Key Discipline Laboratory of Wide Bandgap Semiconductor Technology, School of Advanced Materials and Nanotechnology, Xidian University, Xi'an 710071, People's Republic of China
Trap states in Al0.55Ga0.45N/GaN Schottky-gate high-electron-mobility transistors (S-HEMTs) and Al2O3/Al0.55Ga0.45N/GaN metal-oxide-semiconductor HEMTs (MOS-HEMTs) were investigated with conductance method in this paper. Surface states with time constant of (0.09–0.12) μs were found in S-HEMTs, and electron tunneling rather than emission was deemed to be the dominant de-trapping mechanism due to the high electric field in high Al content barrier. The density of surface states evaluated in S-HEMTs was (1.02–4.67)×1013 eV−1·cm−2. Al2O3 gate insulator slightly reduced the surface states, but introduced low density of new traps with time constant of (0.65–1.29) μs into MOS-HEMTs.
