GaN-Based High-Voltage Light-Emitting Diodes With SU-8 Passivation

The authors propose the use of SU-8 to passivate the isolation trenches of GaN-based high-voltage light-emitting diodes (HV-LEDs). Compared with the HV-LED chips prepared with pure SU-8 passivation, it was found that we could increase the production yield from ≤ 35% to ≥ 88% using properly diluted SU-8 passivation layer. It was also found that we could reduce the passivation layer thickness by diluting SU-8 with a ratio of 5:2. Furthermore, it was found that the properly diluted SU-8 could provide smooth surface, minimized crack formation, and thus larger production yield.