2.5-kV AlGaN/GaN Schottky Barrier Diode on Silicon Substrate with Recessed-anode Structure

TL;DR

This paper presents a high-performance 2.5-kV AlGaN/GaN Schottky barrier diode on silicon with a recessed-anode structure, achieving low turn-on voltage, high breakdown voltage, and excellent power figure-of-merit through optimized fabrication and design.

Contribution

The study introduces a novel recessed-anode structure and fabrication process that significantly improves the performance and breakdown voltage of AlGaN/GaN Schottky diodes on silicon substrates.

Findings

Achieved a low turn-on voltage of 0.71 V with high uniformity.

Demonstrated breakdown voltages up to 2521 V.

Attained a high power figure-of-merit of 1656 MW/cm2.

Abstract

In this letter, we demonstrate high-performance lateral AlGaN/GaN Schottky barrier diodes (SBD) on Si substrate with a recessed-anode structure. The optimized rapid etch process provides results in improving etching quality with a 0.26-nm roughness of the anode recessed surface. By using the high work function metal Pt as the Schottky electrode, a low Von of 0.71 V is obtained with a high uniformity of 0.023 V for 40 devices. Supported by the flat anode recess surface and related field plate design, the SBD device with the anode-cathode spacing of 15 um show the Ron,sp of 1.53 mOhm.cm2 only, the breakdown voltage can reach 1592 V with a high power FOM (Figure-of-Merit) of 1656 MW/cm2. For the SBD device with the anode-cathode spacing of 30 um, the breakdown voltage can be as high as 2521 V and the power FOM is 1244 MW/cm2.