Traps and defects in pre- and post- stressed AlGaN-GaN high electron mobility transistors

✍ Scribed by Sin, Yongkun ;Foran, Brendan ;Joh, Jungwoo ;del Alamo, Jesus A.

• Book ID: 105366064
• Publisher: John Wiley and Sons
• Year: 2011
• Tongue: English
• Weight: 297 KB
• Volume: 208
• Category: Article
• ISSN: 0031-8965
• DOI: 10.1002/pssa.201001079

✦ Synopsis

Abstract

We used deep level transient spectroscopy (DLTS) and HR‐TEM techniques to study traps and defects in pre‐ and post‐stressed AlGaN/GaN high electron mobility transistors (HEMTs) grown by MOCVD on semi‐insulating SiC substrates. DLTS identified two dominant traps with activation energies of 0.5 and 0.7 eV in both pre‐ and post‐stressed GaN HEMTs. Electrical stress resulted in a significant increase in the density of 0.5 eV traps. This is attributed to point defects (most likely N antisites) in the AlGaN barrier and clearly suggests that these traps play a critical role in degradation of the devices. Cross‐sectional TEM confirmed physical damage on the edge of the gate that was likely due to the inverse piezoelectric effect.