Al_0.30Ga_0.70N/GaN/Al_0.07Ga_0.93N Double Heterostructure High Electron Mobility Transistors with a Record Saturation Drain Current of 1050 mA/mm

We report Al_0.30Ga_0.70N/GaN/Al_0.07Ga_0.93N double heterostructure high electron mobility transistors with a record saturation drain current of 1050 mA/mm. By optimizing the graded buffer layer and the GaN channel thickness, both the crystal quality and the device performance are improved significantly, including electron mobility promoted from 1535 to 1602 cm²/V?s, sheet carrier density improved from 0.87×10¹³ to 1.15×10¹³ cm^?2, edge dislocation density reduced from 2.4×10⁹ to 1.3×10⁹ cm^?2, saturation drain current promoted from 757 to record 1050 mA/mm, mesa leakage reduced by two orders in magnitude, and breakdown voltage promoted from 72 to 108 V.