Investigation of Defect Distributions in SiO2/AlGaN/GaN High-Electron-Mobility Transistors by Using Capacitance-Voltage Measurement with Resonant Optical Excitation

• Published in: Journal of the Korean Physical Society Vol. 72; no. 11; pp. 1332 - 1336
• Main Authors: Kim, Tae-Soo, Lim, Seung-Young, Park, Yong-Keun, Jung, Gunwoo, Song, Jung-Hoon, Cha, Ho-Young, Han, Sang-Woo
• Format: Journal Article
• Language: English
• Published: Seoul The Korean Physical Society 01.06.2018; Springer Nature B.V; 한국물리학회
• Subjects: Aluminum gallium nitrides; Capacitance; Defects; Electrical measurement; Energy levels; Excitation; High electron mobility transistors; Investigations; Light; Mathematical and Computational Physics; Particle and Nuclear Physics; Physics; Physics and Astronomy; Semiconductor devices; Silicon dioxide; Theoretical; Threshold voltage; Transistors; 물리학; Resonance excitation; Capacitance-voltage; Interfacial trap; MOS HEMT
• ISSN: 0374-4884; 1976-8524
• DOI: 10.3938/jkps.72.1332

We investigated the distributions and the energy levels of defects in SiO 2 /AlGaN/GaN highelectron-mobility transistors (HEMTs) by using frequency-dependent ( F - D ) capacitance-voltage ( C - V ) measurements with resonant optical excitation. A Schottky barrier (SB) and a metal-oxidesemiconductor (MOS) HEMT were prepared to compare the effects of defects in their respective layers. We also investigated the effects of those layers on the threshold voltage ( V th ). A drastic voltage shift in the C - V curve at higher frequencies was caused by the large number of defect levels in the SiO 2 /GaN interface. A significant shift in V th with additional light illumination was observed due to a charging of the defect states in the SiO 2 /GaN interface. The voltage shifts were attributed to the detrapping of defect states at the SiO 2 /GaN interface.