Fabrication and Characterization of High-Voltage LEDs Using Photoresist-Filled-Trench Technique

We report design, fabrication, and characterization of high-voltage LEDs (HVLEDs) using photoresist-filled-trench technique. Narrow trenches (1 μm wide) were etched to isolate the constituent LED cells of a HVLED chip and then passivated by refilling thermal curable photoresist. With a planarized HVLED surface, only a thin metal layer was needed for inter-cell connection. The narrow trench design ensured uniform light emission and allowed for negligible connection resistance. The optical power of a HVLED with 33 cells reached 1.76 W at 100 mA. The results suggested that HVLED is a viable design option for high-voltage and low current drive applications, with large and uniform light emission areas.