Design and Simulation of Quasi-Vertical GaN Based Junction Barrier Schottky Diode

Abstract

In order to improve the reverse breakdown characteristics of quasi-vertical GaN-based Schottky barrier diode (SBD), a junction barrier Schottky diode (JBS) is designed in this paper, and device modeling and characteristic simulation are carried out. Comparing the SBD and JBS devices with the same epitaxial structure, the breakdown voltages of the devices are 310V and 1145V, respectively. Compared to SBD devices, JBS has a higher breakdown voltage. In order to continue to improve the performance of the device, after optimizing the thickness of the N <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-</sup> GaN drift layer of the JBS device, it is found that increasing the thickness of the N <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-</sup> GaN drift layer can effectively improve the breakdown voltage of the JBS, but the on-resistance of the device also increases slightly. The breakdown voltage of the optimized JBS device is 1812V; the ratio of the area of the Schottky contact area to the area of the PiN area will also affect the performance of the vertical JBS device, and the area ratio of the Schottky contact area is increased from 0.379 to 0.67, the on-resistance of the device is reduced from 1.097mΩ•cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> to 0.747 mΩ•cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , and the reverse breakdown voltage is slightly reduced. The research results provide a theoretical reference for device structure design and process fabrication.