Fabrication of AlGaN/GaN High Electron Mobility Transistors

摘要

In this paper, the growth and device fabrication of AIGaN/GaN HEMTs are investigated by using Metal-Organic Vapor Phase Epitaxy (MOVPE) system. The grown wafer consists of a 3-μm-thick unintentionally doped GaN buffer layer, an undoped AlGaN spacer layer, and a n-doped Al_(0.28)Ga_(0.72)N cap layer. The growth condition and the wafer structure are optimized for high performance devices. The devices exhibit a maximum saturation current density of 1000 mA/mm, good pinch off at -5V gate bias and a peak extrinsic transconductance of 180 mS/mm. Further efforts to improve the device performance are also discussed.