Thin Film GaN LEDs Using a Patterned Oxide Sacrificial Layer by Chemical Lift-Off Process

A high-quality GaN-based vertical light-emitting diode (LED) was successfully fabricated and transferred to an electroplated Cu substrate using strip-patterned silicon dioxide (SiO2) as a sacrificial layer in a chemical lift-off (CLO) process. The SiO2 strip patterns not only provide the sacrificial structure during the detachment process, but also improve the quality of GaN epilayers through epitaxial lateral overgrowth. Compared with conventional LEDs, the CLO-LEDs have a higher output power and a lower forward voltage. The CLO-LED has a decrease in forward voltage of 0.42 V (at 20 mA) as compared with the conventional LED. In addition, at a drive current of 350 mA, the output power of CLO-LEDs is enhanced similar to 2.2 fold, compared with that of conventional LEDs.