設施農業：節能栽培與滅菌【國立暨南國際大學應用材料及光電工程學系/國立中興大學材料科學與工程學系/武東星 校長/客座教授】
| 論文篇名 | 英文：High Performance AlGaInP-Based Micro-LED Displays With Novel Pixel Structures 中文：新型圖元結構之高性能AlGaInP微發光顯示器 |
| 期刊名稱 | IEEE PHOTONICS TECHNOLOGY LETTERS |
| 發表年份,卷數,起迄頁數 | 2021, 33(24), 1375-1378 |
| 作者 | Chang, Kai-Ping; Lien, Po-Chun; Yen, Chao-Chun; Chen, Po-Wei; Horng, Ray-Hua; Wuu, Dong-Sing(武東星)* |
| DOI | 10.1109/LPT.2021.3123447 |
| 中文摘要 | 採用晶圓接合、圖片式金屬接觸層和側壁鈍化層，改進了基於AlGaInP的倒裝式微發光二極體(µ-LED)陣列晶片的製備技術和光提取效率。將含有銦錫氧化物(ITO)的膜成功地從GaAs基板轉移到藍寶石基板上並結合。採用三種類型的圖紋n-金屬作為自對準光罩和光反射層，其中n-GaAs層可通過濕法刻蝕去除部分。將BCl3氣體應用於電感耦合等離子體(ICP)系統中，優化了MESA的刻蝕，抑制了邊牆的刻蝕速率，提高了刻蝕深度的均勻性。在−5 V的偏置下，µ-LED陣列晶片的漏電流從85 nA降低到7 nA。此外，設計了三種帶全向反射(ODR)的金屬接觸/n-GaAs結構，以降低發射光吸收，鈍化MESA側壁，提高輸出功率。最後，與驅動IC結合後，實現了0.52 吋的紅色µ-LED陣列，晶片尺寸為100 μ m × 100 μ m，解析度為138 pixels/in。因此，與具有SiO2鈍化層和n-金屬非圖像化接觸的晶片相比，具有ODR和圖像化接觸的晶片外量子效率最高，為51.1%，相對輸出功率增強441%。 |
| 英文摘要 | The fabrication process and light extraction efficiency of AlGaInP-based flip-chip micro- light-emitting diode (µ-LED) array chips are improved by employing a wafer-bonding process, patterned metal contact, and sidewall passivation layers. The epilayers with indium tin oxide (ITO) can be successfully transferred from the GaAs substrate to the sapphire substrate and bound. Three types of patterned n-metal are employed in the µ-LED as a self-aligning mask and light reflection layer, where the n-GaAs layer can be partially removed by the wet etching process. The dry etching process of MESA has been optimized by applying the BCl3 gas in the inductively coupled plasma (ICP) system, which can suppress the etching rate of the sidewall and improve the etching depth uniformity. Consequently, the leakage current of the µ-LED array chip is decreased from 85 to 7 nA under the bias of −5 V. Moreover, three configurations of the metal contact/n-GaAs structures with Omnidirectional reflector (ODR) have been designed to reduce the emission light absorption, passivating the sidewall of MESA, and enhance the output power. Finally, the 0.52-in red µ-LED array with a chip size of 100 µm × 100 µm and resolution of 138 pixels/in is realized when bonded with the drive IC. Consequently, the µ-LED array chips with ODR and patterned contact show the highest external quantum efficiency of 51.1% and relative output power enhancement of 441% compared to the chip with SiO2 passivation layer and nonpatterned n-metal contact. |
| 發表成果與本中心研究主題相關性 | 針對紅光覆晶 LED 提出光輸出改善方案，包括結構穿透率評估、晶片貼合壓力、Mesa 蝕刻、退火溫度最佳化等，並藉由蝕刻 n-GaAs 提高垂直方向阻抗， 改善電流均勻性，由於 n-GaAs 會吸收 630 nm 波段的光，降低 n-GaAs 面積，因此提出n-GaAs 蝕刻圖案，優化提高光輸出功率，並降低電流擁擠效應，可應用於農業栽培之高效率光源。 |
