Design and Fabrication of Vertical GaN p-n Diode With Step-Etched Triple-Zone Junction Termination Extension
Hyunsoo Lee, Yuxuan Zhang, Zhaoying Chen, Mohammad Wahidur Rahman, Hongping Zhao, Siddharth Rajan
Abstract
We demonstrate edge termination for vertical GaN p-n diodes using step-etched triple-zone junction termination extension (JTE). The technique was found to yield high breakdown efficiency without degradation of forward characteristics. The electric field distribution at various JTE thicknesses was simulated, and the experimental results were well matched to the simulation results. The fabricated GaN p-n diode with step-etched triple-zone JTE shows a breakdown voltage of 550 V corresponding to a junction termination efficiency of 75%, with a turn-on voltage of 3.1 V, a specific ON-resistance of 1.3 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{m}\Omega \cdot $ </tex-math></inline-formula> cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , and leakage current at −200 V of 80 nA/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . The multistep JTE strategy demonstration could be important for future applications for multikilovolt-class GaN vertical power devices.