High-efficiency submicron GaN micro-LEDs fabricated by neutral beam etching

Micron or even submicron GaN micro-LEDs are highly required from AR microdisplays. However, fabrication of high-efficiency submicron GaN micro-LEDs remains a significant technical challenge due to the existence of strong sidewall nonradiative recombination induced by ICP etching. We employed an ultralow damage dry etching technique, i.e., neutral beam etching, to fabricate GaN micro-LEDs. In this technique, charged ions are transformed into a beam of neutral particles when ions passed through apertures opened in a carbon plate placed between plasma discharge and etching chamber, thus enabling ultralow damage etching of various materials. We have demonstrated 3.5 3.5 m 2 GaN blue micro-LEDs with negligible sidewall nonradiative recombination by using the neutral beam etching technique [1]. We further extended this technique to the fabrication of submicron GaN micro-LEDs. In this talk, I will present recent progresses on the fabrication of submicron GaN micro-LEDs, including the demonstration of a GaN micro-LED with a diameter as small as 200 nm. [1] X. L. Wang, et al., Nat. Commun. 14 (2023) 7569.