Chemical lift‐off process for nitride LEDs from an Eco‐GaN template using an AlN/strip‐patterned‐SiO2 sacrificial layer

In this research, a nitride light‐emitting diode (LED) fabricated on an electroplated Cu substrate can be removed from a GaN/sapphire (Eco‐GaN) template by conducting the chemical lift‐off (CLO) process using an AlN/strip‐patterned‐SiO 2 intermediate sacrificial layer. The regrowth GaN epilayer deposited on AlN/patterned SiO 2 /Eco‐GaN can achieve a high crystal quality via the epitaxial lateral overgrowth process. To etch the patterned SiO 2 and AlN layers, the HF and 80 °C‐KOH solutions were used, respectively. Due to the use of low‐temperature KOH solution, the GaN epilayer would suffer less damage during the CLO process, improving the reuse feasibility for the Eco‐GaN template. Moreover, when the etching treatment was used for the AlN layer, a highly lateral etching rate of 0.5 mm h −1 was achieved. Compared to the conventional LED, the vertical‐type LED/Cu substrate had a higher output power of 212 mW (at 350 mA). Based on our estimation, the output power of LED prepared on Cu substrate had an 86% improvement in comparison to that of conventional LED. Obviously, the good optoelectronic performance of the LED/Cu device can be obtained after performing the CLO process. Furthermore, the separated Eco‐GaN template has high potential for reuse applications, indicating that this technique is helpful to the cost‐effective LED fabrication.