Title :
Thin Film GaN LEDs Using a Patterned Oxide Sacrificial Layer by Chemical Lift-Off Process
Author :
Shih-Hao Chuang ; Chun-Ting Pan ; Kun-Ching Shen ; Sin-Liang Ou ; Dong-Sing Wuu ; Ray-Hua Horng
Author_Institution :
Dept. of Mater. Sci. & Eng., Nat. Chung Hsing Univ., Taichung, Taiwan
Abstract :
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 ~ 2.2 fold, compared with that of conventional LEDs.
Keywords :
III-V semiconductors; copper; electroplating; epitaxial growth; gallium compounds; light emitting diodes; semiconductor thin films; silicon compounds; wide band gap semiconductors; Cu; GaN; SiO2; chemical lift-off process; current 350 mA; detachment process; drive current; electroplated substrate; epilayers; epitaxial lateral overgrowth; forward voltage; patterned oxide sacrificial layer; sacrificial structure; strip patterns; strip-patterned silicon dioxide; thin film LED; vertical light-emitting diode; voltage 0.42 V; Etching; Gallium nitride; Light emitting diodes; Performance evaluation; Rough surfaces; Substrates; Chemical lift-off; electroplating; epitaxial lateral overgrowth; light-emitting diode (LED); strip-patterned ${rm SiO}_{2}$;
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2013.2287892