Vertical GaN PIN Structure with Intrinsic AlGaN Drift Layer Grown Using Metal‐Organic Chemical Vapor Deposition

In this study, it is aimed to examine the DC characteristics of a vertical PIN diode featuring AlGaN as the drift layers. In the investigation, observing the changes in DC characteristics with the variation of Al content (0%–4%) in the drift layers as well as its thickness is focused on. By applying AlGaN as the drift layer, the semi‐insulating properties are augmented and the detrimental background carbon impurity is reduced, leading to a reduction in the leakage current and an improvement in the breakdown voltage characteristics of the device. Room‐temperature and low‐temperature photoluminescence measurements confirm a reduction in the intensity of both yellow luminescence and blue luminescence, which can be attributed to the decrease in defect concentration. Furthermore, to minimize the occurrence of premature breakdown voltage, p‐type GaN is meticulously etched into a bevel shape, and subsequent confirmation through the utilization of a scanning electron microscope reveals an inclination of 13°. The outcome of the analysis on the DC characteristic indicates an improvement in reverse‐bias characteristics with the increase in the Al ratio in the drift layer for the 2 μm series. Furthermore, for the 20 μm Al0.04Ga0.96N, a breakdown voltage of 2540 V is recorded. The study examines the impact of aluminum content (0%–4%) and drift layer thickness on DC characteristics and breakdown voltage in vertical GaN‐on‐GaN PIN diodes. Using PL and AFM, surface and defects of the drift layers are analyzed. A device with a 20 μm Al0.04Ga0.96N drift layer achieves a breakdown voltage of 2540 V.