The study of the contribution of the surface and bulk traps to the dynamic Rdson in AlGaN/GaN HEMT by light illumination

The effects of the surface and bulk traps on current collapse in AlGaN/GaN high electron mobility transistor were investigated by the transient behaviors of the devices. The results proved that the traps at the surface had little effect on current collapse when the device was well passivated, but the traps in the buffer layer played an important role. Two bulk trap levels were observed in these devices. In addition, the effects of light illumination on the bulk traps were studied in detail. It was found that light illumination enhanced the resumption of the current collapse after the field stress. The contribution of lights illumination with various wavelengths to the current collapse was also investigated to study the trap energy levels.