GaN-based light-emitting diodes prepared with shifted laser stealth dicing

We propose a simple shifted laser stealth dicing (shifted-LSD) method to enhance output power of GaN-based blue light-emitting diodes (LEDs). Compared with the conventional method with only one nanosecond laser scribing from the front side, we performed two additional picosecond laser scribing on different positions of the backside surface. It was found that we could effectively enhance the LED output power from 132.14 to 139.11 mW using the shifted-LSD without degrading the electrical properties of the devices. It was also found such enhancement should be attributed to the enhanced LEE from the roughened sapphire substrate.