Degradation mechanism of 0.15 um AlGaN/GaN HEMTs: effects of hot electrons

TL;DR

This study investigates how hot electrons contribute to the degradation of 0.15 um AlGaN/GaN HEMTs with Fe and C co-doping, revealing mechanisms involving trap activation and damage to device contacts.

Contribution

It provides new insights into the degradation mechanisms of AlGaN/GaN HEMTs under hot-electron stress, focusing on the effects of doping and trap activation.

Findings

Hot-electron stress activates pre-existing traps in the buffer.

Degradation involves attenuation of electric field and damage to gate contact.

Parametric changes observed during stress tests support the proposed mechanism.

Abstract

The degradation mechanisms of AlGaN/GaN HEMTs adopting Fe and C co-doping, with high and low carbon doping concentration were investigated by means of hot-electron step stress and 24 hours stress tests. Firstly, DC and EL characterization at room temperature are summarized, then the parametric evolution during hot-electron step stress tests at the semi-on state was compared, the assumption for the degradation mechanism is that hot-electrons activated the pre-existing traps in the buffer, attenuate the electric field in the gate drain access region and damaging the gate contact, the parametric evolution during constant stresses is discussed.