Pu Taofei, Younis Usman, Chiu Hsien-Chin, Xu Ke, Kuo Hao-Chung, Liu Xinke
College of Materials Science and Engineering, Shenzhen University-Hanshan Normal University Postdoctoral Workstation, Shenzhen University, Shenzhen, 518060, China.
Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060, China.
Nanoscale Res Lett. 2021 Jun 7;16(1):101. 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.
作为一种典型的宽带隙半导体材料，氮化镓（GaN）因其优异的材料特性（如高电子迁移率、高电子饱和速度和临界电场）而受到越来越多的关注。垂直氮化镓器件已得到研究，被视为电力电子应用中最有前途的候选器件之一，其特点是具有高电压、高电流和高击穿电压的能力。在这些器件中，基于垂直氮化镓的PN结二极管（PND）已得到大量研究，并在高质量外延和器件结构设计的基础上展现出巨大的性能进步。然而，其器件外延质量仍需进一步提高。在器件电性能方面，器件边缘的电场拥挤效应是一个亟待解决的问题，这会导致过早击穿并限制氮化镓材料优势的发挥，但目前可通过边缘终端技术来缓解。本综述重点介绍了材料外延生长和边缘终端技术的进展，随后探讨了当前氮化镓的发展情况以及与碳化硅（SiC）相比在材料和器件方面的潜在优势、氮化镓肖特基势垒二极管（SBD）和PND在机理和特性方面的差异，以及垂直器件相对于横向器件的优势。然后，本综述给出了展望，并揭示了用于电力系统的垂直氮化镓PND的设计趋势，包括早期的垂直氮化镓PND。
