以側壁修復技術提升小尺寸微發光二極體發光效率

隨著顯示技術的發展，傳統的LCD在滿足小型化和高亮度的需求方面已經受到挑戰。微型發光二極管（Micro-LED）在亮度和尺寸方面具有巨大優勢。然而，Micro-LED的發光效率仍然不足，主要原因是隨著器件尺寸的減小，側壁所佔整體表面積的比例增加，而蝕刻造成的側壁損傷導致的側壁非輻射重組現象嚴重。我們提出了一種數字蝕刻技術，該技術採用多步蝕刻和處理，以減輕台面乾蝕刻後暴露的側壁缺陷。在這項研究中，通過對兩步蝕刻後的器件側壁進行了N2處理，元件正向相電流增加，同时由于側壁缺陷減少，使得因側壁非輻射復合所產生的方向漏電也相應減小。結果顯示，與只有一步蝕刻而不處理的情況相比，數字蝕刻的10 × 10 μm2 元件的光輸出功率增加了92.6 %。此外，與不進行數字蝕刻的100 × 100 μm2元件相比，10 × 10 μm2元件的光輸出密度只減少了1.1 %。因此兩次蝕刻和處理可以有效地抑制側壁損傷，降低反向漏電，提高元件的發光效率。

關鍵字

發光二極體；數字蝕刻； N2處理；側壁缺陷；表面非輻射復合

並列摘要

The decrease of light output efficiency with the shrink of LED (light-emitting diode) die size is one of the challenges of micro-LED displays. Micro light-emitting diode (Micro-LED) has enormous advantages in brightness and size. However, the efficiency of Micro-LEDs is still lacking in luminescence, mainly because the proportion of the overall surface area occupied by the sidewalls increases as the size of the devices decreases, and the sidewall non-radiation recombination due to sidewall damage caused by etching is severe. We propose a digital etching technology which employs multi-step etching and treatment to mitigate sidewall defects exposed after mesa dry etching. In this study, the N2 treatment of the sidewalls of the devices after two-step etching resulted in an increase in the forward phase current of the components and a reduction in the directional leakage due to non-radiative restoration of the sidewalls as a result of the reduction in sidewall defects. An increase of light output by 83.67 % is observed for 10 × 10 μm2 with digital etching, as compared with that with only one step etching and no treatment. It also shows only 1.1 % decrease in optical output density for 10 × 10 μm2 LEDs, as compared with 100 × 100 μm2 device without performing digital etching. The results showed that twice etched and treated can effectively improve the luminescence efficiency of the devices.

並列關鍵字

light-emitting diode ； digital etching ； N2 treatment ； sidewall defects ； non-radiative recombination

參考文獻

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