Alleviate sidewall damage of InGaN green micro-LEDs by atomic layer etching

In this work, atomic layer etching (ALE) technology is demonstrated to alleviate the sidewall damage generated during the mesa etching process of InGaN micro-LEDs. TEM images verify the existence of the sidewall damage and its mitigation after 200-cycle ALE sidewall treatment. The defect-related leakage current density significantly decreases from 3 × 10^-5 to 7 × 10^-6 A/cm² at -20 V bias through sidewall treatment. InGaN green micro-LEDs (11 µm) with ALE sidewall treatment show a more than 10% enhancement in external quantum efficiency compared to untreated reference devices. This work provides a new, to our knowledge, perspective on addressing the sidewall effect in micro-LEDs, aiding the realization of high-efficiency InGaN micro-LEDs in the near term.