Novel E-mode GaN high-electron-mobility field-effect transistor with a superlattice barrier doped with Mg by thermal diffusion

Abstract

A novel E-mode gallium nitride (GaN) high-electron-mobility field-effect transistor (HEMT) was prepared by combining a superlattice barrier with Mg by thermal diffusion doping. The new device can effectively overcome the disadvantages of the conventional p-GaN gate E-mode HEMT process, which include high etching accuracy requirements, difficult p-type doping, weak gate control, and large gate leakage. The device obtained in this study has a threshold voltage of 1.17 V, an output current of 227 mA mm⁻¹ at V_G = 3 V, a gate leakage of 2.0 × 10⁻⁸ mA mm⁻¹ at V_G = 0 V, and a breakdown voltage of up to 405 V. The high-voltage, low-gate-leakage current power device developed in this work could be used as a new type of E-mode power device.