Review of Recent Progress on Vertical GaN-Based PN Diodes

• Published in: Nanoscale research letters Vol. 16; no. 1; p. 101
• Main Authors: Pu, Taofei, Younis, Usman, Chiu, Hsien-Chin, Xu, Ke, Kuo, Hao-Chung, Liu, Xinke
• Format: Journal Article
• Language: English
• Published: New York Springer US 07.06.2021; Springer Nature B.V; SpringerOpen
• Subjects: Breakdown; Chemistry and Materials Science; Devices; Edge termination techniques; Electric fields; Electric power systems; Electrical field crowding; Electron mobility; Epitaxial growth; Epitaxy; Gallium; Gallium nitride; Gallium nitrides; High voltage; Junction diodes; Material properties; Materials Science; Molecular Medicine; Nano Review; Nanochemistry; Nanoscale Science and Technology; Nanotechnology; Nanotechnology and Microengineering; P-n junctions; Reviews; Schottky diodes; Semiconductor materials; Silicon carbide; Vertical PN junction diode; Voltage; Wide bandgap semiconductors; Electrical field crowding; Edge termination techniques; Vertical PN junction diode; Gallium nitride
• ISSN: 1556-276X; 1931-7573; 1556-276X
• DOI: 10.1186/s11671-021-03554-7

As a representative wide bandgap semiconductor material, gallium nitride (GaN) has attracted increasing attention because of its superior material properties (e.g., high electron mobility, high electron saturation velocity, and critical electric field). Vertical GaN devices have been investigated, are regarded as one of the most promising candidates for power electronics application, and are characterized by the capacity for high voltage, high current, and high breakdown voltage. Among those devices, vertical GaN-based PN junction diode (PND) has been considerably investigated and shows great performance progress on the basis of high epitaxy quality and device structure design. However, its device epitaxy quality requires further improvement. In terms of device electric performance, the electrical field crowding effect at the device edge is an urgent issue, which results in premature breakdown and limits the releasing superiorities of the GaN material, but is currently alleviated by edge termination. This review emphasizes the advances in material epitaxial growth and edge terminal techniques, followed by the exploration of the current GaN developments and potential advantages over silicon carbon (SiC) for materials and devices, the differences between GaN Schottky barrier diodes (SBDs) and PNDs as regards mechanisms and features, and the advantages of vertical devices over their lateral counterparts. Then, the review provides an outlook and reveals the design trend of vertical GaN PND utilized for a power system, including with an inchoate vertical GaN PND.