Robust Avalanche in 1.7 kV Vertical GaN Diodes With a Single-Implant Bevel Edge Termination
Robust Avalanche in 1.7 kV Vertical GaN Diodes With a Single-Implant Bevel Edge Termination
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DOI：
10.1109/led.2023.3302312
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发表时间：
2023-10
影响因子：
4.9
通讯作者：
M. Xiao;Y. Wang;Ruizhe Zhang;Q. Song;M. Porter;E. Carlson;K. Cheng;K. Ngo;Yuhao Zhang
中科院分区：
文献类型：
--
作者：
M. Xiao;Y. Wang;Ruizhe Zhang;Q. Song;M. Porter;E. Carlson;K. Cheng;K. Ngo;Yuhao Zhang
本工作展示了一种用于垂直GaN p-n二极管的具有渐变电荷分布的新型结终端扩展(JTE)。这种JTE的制作省去了GaN刻蚀，只需要一次注入。双层光致抗蚀剂被用来在介电层的侧壁产生超小的斜角($\sim 0.1^{\text{o}}{)}$。然后将这种渐变的介质层用作注入掩模，以在p-GaN中产生渐变电荷分布。所制备的GaN p-n二极管的击穿电压(BV)为1.7kV(平行面极限的83%)，具有正的温度系数，在未钳位的电感开关测试中，BV处的雪崩电流密度超过1100A/cm2。这种强劲的雪崩归因于主要碰撞电离位置从JTE边缘迁移到主结。这种单注入、高效、抗雪崩的JTE有可能成为许多垂直GaN器件的构建块，其制造技术具有广泛的器件和材料适用性。
This work demonstrates a novel junction termination extension (JTE) with a graded charge profile for vertical GaN p-n diodes. The fabrication of this JTE obviates GaN etch and requires only a single-step implantation. A bi-layer photoresist is used to produce an ultra-small bevel angle ( $\sim 0.1^{\text {o}}{)}$ at the sidewall of a dielectric layer. This tapered dielectric layer is then used as the implantation mask to produce a graded charge profile in p-GaN. The fabricated GaN p-n diodes show a breakdown voltage (BV) of 1.7 kV (83% of the parallel-plane limit) with positive temperature coefficient, as well as a high avalanche current density over 1100 A/cm2 at BV in the unclamped inductive switching test. This robust avalanche is ascribed to the migration of the major impact ionization location from the JTE edge to the main junction. This single-implant, efficient, avalanche-capable JTE can potentially become a building block of many vertical GaN devices, and its fabrication technique has wide device and material applicability.