The effect of the intrinsic layer on the reliability of nitride-based p–i–n photodetectors

This study successfully proves that the reliability of nitride-based p–i–n photodetectors (PDs) is highly sensitive to the thickness of intrinsic GaN layers. Results are based on i-GaN layers of 0.25 µm, 0.4 µm and 0.5 µm thicknesses. After current ageing, the p–i–n PDs with thin i-layers exhibited poor electrical strength. Increasing the thickness of the i-layer improved the electrical strength and ESD protection capability of PDs. This result is directly related to the impedance and dislocation density of the i-layer. However, the etched sidewall becomes a weak point when adopting a thicker i-layer.