Investigation of Reliability Issues in InAlGaN/GaN and InAlN/GaN HEMTs

Abstract: Gallium nitride (GaN) high electron mobility transistors (HEMTs) have emerged as promising devices for high-power and high-frequency applications due to their wide bandgap, high breakdown electric field, and superior switching performance. However, charge trapping under high electric field operation leads to reliability degradation, limiting their widespread deployment. This seminar presents a comprehensive investigation of the reliability mechanisms in InAlGaN and InAlN/GaN HEMTs.

The first part of the work focuses on threshold voltage (Vth) instability, dynamic ON-resistance (RON) degradation, and current collapse in InAlGaN HEMTs. Temperature-dependent gate leakage characterization and analytical modeling reveal enhanced trap-assisted and defect-assisted tunneling arising from lattice-mismatch-induced barrier defects. The effectiveness of Al2O3-based MIS-HEMTs in suppressing gate leakage and improving VTH stability is also demonstrated.

The second part investigates the reliability of carbon-doped InAlN/GaN HEMTs, including the first demonstration of the kink effect in power HEMTs. The study further explores hot-electron-assisted detrapping, substrate-bias-induced kink effects, and 2DHG-mediated cross-talk-induced kink effects, providing new insights into charge trapping and degradation mechanisms in GaN HEMTs for reliable power electronic applications.

Event Details
Title: Investigation of Reliability Issues in InAlGaN/GaN and InAlN/GaN HEMTs
Date: August 17, 2026 at 03:00 PM
Venue: ESB244
Speaker: Ms. Pallavi Kumari (EE21D014)
Guide: Dr. Nandita DasGupta
Type: PHD seminar