Electron transport properties in high electron mobility transistor structures improved by V-Pit formation on the AlGaN/GaN interface

This work proposes a new morphology for the AlGaN/GaN interface that improves the electron mobility of the two-dimensional electron gas (2DEG) in high-electron mobility transistor (HEMT) structures. Replacing the high-temperature GaN channel layer (used in the majority of HEMTs) with a layer grown at 870°C in an N₂ atmosphere using TEGa as a precursor significantly increases the electron Hall mobility. This unexpected behaviour is explained by the presence of V-pits which spatially separate electrons from regions surrounding dislocations that contain an increased concentration of point defects and impurities.