Impact of AlGaN Back Barrier in AlGaN/GaN HEMT on GaN substrate

The DC and high frequency performance of AlGaN/GaN HEMT device with and without the AlGaN back barrier was studied and the performance of the devices are compared. Introducing the back barrier helps in lifting up the conduction band and thus minimizes the leakage path under the buffer layer and also helps in confining the 2DEG in the narrow channel. Also with the introduction of the back barrier, the drain leakage current in the subthreshold region is significantly minimized and the DC charecteristics of AlGaN/GaN HEMT is preserved. At the same time the RF performance is enhanced by reducing the short channel effects.