Performance improvement of AlGaN based deep-ultraviolet micro-LED arrays by optimizing radio frequency power of inductively coupled plasma etching

Inductively coupled plasma (ICP) etching is a key step in device fabrication of AlGaN-based deep ultraviolet (DUV) micro light-emitting diodes (Micro-LEDs). By optimizing the radio frequency (RF) power parameters during the ICP etching process, an appropriate RF power could be adopted to reduce etching damage and light loss during the light transmission process. It can be obtained in this work that employing RF power that is too large during the ICP process will introduce more defects into the active region, which will form more nonradiative recombination centers and reduce carrier lifetime and injection efficiency. However, employing RF power that is too small will lead to smaller etching angles, which will increase light loss during the light transmission process. In this study, AlGaN-based DUV Micro-LED arrays with an emission wavelength of 278 nm were fabricated using an optimal RF power of 100 W. This approach significantly mitigated both sidewall damage and optical transmission loss, resulting in a 17.4% enhancement of light output power.