IEEE Workshop on Wide Bandgap Power Devices and Applications in Asia (WiPDA Asia 2018)

254 / 2017-11-22 22:15:38

Influence of the oxygen in Hot-Carrier-Stress-Induced degradation in AlGaN/GaN high electron mobility transistors

AlGaN/GaN,high electron mobility transistor,stresss,oxygen,reliability

Plenary track > Device characterization and modeling

In this study, the role of the oxygen in AlGaN/GaN HEMTs before and after semi-on state stress were discussed. Comparing with the electrical characteristics of the devices in vacuum, air and oxygen atmosphere, it is revealed that the oxygen has significant influence on the characteristics and the degradation of the device after semi-on state electric stress. Comparing with in the vacuum, the gate current increased an order magnitude in the oxygen and the air atmosphere. While the maximum drain current increased more obviously in saturated region than that of in linear region, which means the characteristic of the devices in the oxygen is related to the electric field between the gate and the drain. During semi-on state electric stress with oxygen, the electric-field-driven oxidation process promoted the oxidation of the nitride layer. Meanwhile, the hot carriers present in the channel during semi-on state stress may scatter to the AlGaN/SiN interface to reduce the oxygen molecules to O2- or generate hole- electron pairs via impact ionization.