Enhanced Electrical Performance and Heat Dissipation in AlGaN/GaN Schottky Barrier Diodes Using Hybrid Tri-anode Structure

Abstract

Abstract-Enhanced performance in AlGaN/GaN Schottky barrier diodes (SBDs) is investigated using a nanowire hybrid tri-anode structure that integrates three-dimensional Schottky junctions with tri-gate transistors. The fabricated SBDs presented an increased output current density with improved linearity, above 1 A/mm at 5 V when normalized by effective anode width, over 3 orders of magnitude lower reverse leakage current and superior heat dissipation. The sidewall Schottky contacts reduced the turn-on voltage and eliminated the non-ideality caused by the AlGaN barrier. The large surface area of tri-gate architecture greatly enhanced heat dissipation and largely reduced the average temperature as well as thermal resistance of the integrated tri-gate transistors. The trench conduction near SiO2/GaN interface, formed under forward bias at both sidewalls and bottom of nanowire trenches, compensated part of the self-heating degradation and improved the output linearity of the device. Optimal design for the tri-anode structure, based on a model of critical filling factor, was proposed to surmount the issue of partial removal of two-dimensional electron gas (2DEG), unveiling the potential of nanostructured GaN devices to achieve comparable or even larger output current than counterpart planar devices.

900 V Reverse-Blocking GaN-on-Si MOSHEMTs With a Hybrid Tri-Anode Schottky Drain

“…The sidewall metal in the tri-anode region ( Fig. 1(e)) forms a direct Schottky contact to the 2DEG and leads to a small VON [15,16]. In OFFstate, VSCH is pinned at the |Vp| of the tri-anode region, which can be very small due to the elastic relaxation of the AlGaN/GaN nanowires [17], [18] and additional electrostatic control from the sidewall metals [19]- [28], resulting in a small IR [13]- [14].…”

High-Voltage and Low-Leakage AlGaN/GaN Tri-Anode Schottky Diodes With Integrated Tri-Gate Transistors

“…Novel nanostructured AlGaN/GaN SBDs based on a hybrid combination of tri-anode and tri-gate architectures have been proposed [14] and investigated in our previous studies [15], [16], which yielded a reduced Von, an improved ideality factor, a diminished IR, and an enhanced heat dissipation of the SBDs, at the expense of a larger Ron and a smaller current capability. In addition, the potential of this architecture for high-voltage power SBDs has not been presented.…”

Field Plate Design for Low Leakage Current in Lateral GaN Power Schottky Diodes: Role of the Pinch-off Voltage

“…ateral AlGaN/GaN SBDs are very promising for power conversions, offering excellent properties for high-voltage, high-power-density and high-frequency operation [1]- [10]. In addition, these devices can be monolithically integrated with GaN high electron mobility transistors (HEMTs) on large-size silicon substrates, which is highly desirable to reduce the cost, size and parasitics for future GaN power converters.…”