ESD Behavior of AlGaN/GaN HEMT on Si: Physical Insights, Design Aspects, Cumulative Degradation and Failure Analysis

This experimental study reports ESD failure analysis of AlGaN/GaN HEMTs. Effect of MESA isolation, gate and parasitic MESA Schottky diode on ESD robustness is studied. Cause of snapback instability, multiple NDCs and transition from soft-to-hard failure are discussed. Unique leakage trends and cumulative nature of degradation are discovered. Post failure analysis reveals role of inverse piezoelectric effect, fringing electric field, contact resistivity, temperature and field induced contact metal migration in degradation of AlGaN/GaN HEMTs under ESD conditions.