Analysis of Varied Dielectrics as Surface Passivation on AlGaN/GaN HEMT for Analog Applications

• Published in: 2018 6th Edition of International Conference on Wireless Networks & Embedded Systems (WECON) pp. 15 - 18
• Main Authors: Madan, Jaya, Pandey, Rahul, Arora, Henika, Chaujar, Rishu
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.11.2018
• Subjects: AlGaN/GaN HEMT; Aluminum gallium nitride; Aluminum oxide; Gallium nitride; Hafnium compounds; HEMTs; HfO 2; High-k Passivation; Passivation; Si 3 N 4 Passivation; Wide band gap semiconductors
• DOI: 10.1109/WECON.2018.8782074

In this work, AlGaN/GaN HEMT device performance for different dielectrics as surface passivation have been studied. Due to the high thermal stability, high dielectric constant and high reliability of HfO 2 but limiting interface quality, a stack of silicon nitride with hafnium dioxide has been proposed as surface passivation material for AlGaN/GaN HEMT, attributed to the good interface of Si 3 N 4 with GaN. The device performance of AlGaN/GaN HEMTs with various dielectrics i.e. SiO 2 , Si 3 N 4 , Al 2 O 3 and a stack of Si 3 N 4 /HfO 2 as surface passivation layer (SPL) have also been compared using device simulator. Evaluated electrical parameters show that the device passivated with a stack of Si 3 N 4 /HfO 2 shows high drain current, high breakdown voltage, higher gain as well as higher current switching ratio in comparison with other dielectric materials used as surface passivation, thus the results indicate that the AlGaN/GaN HEMT with stack (Si 3 N 4 /HfO 2 ) surface passivation has better device performance suitable for high-power applications.