Investigation of the Electrostatic Discharge Performance of GaN-Based Light-Emitting Diodes With Naturally Textured p-GaN Contact Layers Grown on Miscut Sapphire Substrates

The electrostatic discharge (ESD) characteristics of GaN-based light-emitting diodes (LEDs) with naturally textured p-GaN contact layers grown on c-axis miscut sapphire substrates are studied and demonstrated. Based on the machine model, the device grown on a 0.35° miscut sapphire shows the highest ESD tolerance, whereas the device grown on a 0.2° miscut sapphire exhibits the poorest tolerance. It is found that this phenomenon is primarily related to the presence of maximum capacitance Cm values rather than the difference in defect densities between LEDs. The variation in Cm values is caused by the parasitic capacitance effect induced by different p-GaN surface morphologies between the studied devices. This observation gives us a more reliable application in improving the ESD performance based on the device grown on a 0.35° miscut sapphire.