應用複合型金屬基板提升n-side up磷化鋁銦鎵 紅光發光二極體特性之研究

本論文開發了一種以銅釩銅(Copper Invar Copper, CIC)當作複合型金屬基板的n型接面向上(N-side up)垂直紅光發光二極體(Light-emitted-diode, LED)，其尺寸為40mil×40mil，我們以磊晶膜轉移技術將原有的砷化鎵基板取代為CIC基板，並解決在使用CIC基板所面臨的各種問題，例如:CIC基板被氨水溶液所侵蝕、乾蝕刻光阻碳化。在晶圓接合製程中，我們運用金錫金屬當作接合層，使用金-錫接合為最佳選擇，不僅能提升基板轉移良率至90%以上並且基板無翹曲的問題。利用接合完成的基板嘗試進行高溫熱退火，退火溫度為340、350、360、370、380oC，發現在360 oC 氮氣下退火所獲得的電阻最小，且呈現歐姆接觸(Ohmic contact)，其電阻為96 Ω；亦以進行壽命量測進行LED/CIC可靠度分析，來判定晶圓接合情況下LED/CIC之壽命，經過672小時測試，CIC/LED元件特性皆符合商用LED可靠度之要求。本實驗室所開發以CIC基板的LED與市面上最成熟以矽基板的LED和正要開發的銅鎢基板LED比較，不僅光功率飽和之電流在900 mA才發生，優於正在開發中銅鎢基板，而所獲取的光波長變化量亦低於矽基板，變化量值為0.02 nm/mA，熱阻量測為8.22 K/W。綜觀上述，由於銅鎢基板成本遠高於CIC基板，又利用矽基板所製成的LED其發光波長變異量大於CIC基板，因此本論文將利用CIC基板所製成的LED進行探討並將利用於高功率LED產業上。

關鍵字

銅釩銅基板；紅光發光二極體；晶圓貼合；磊晶膜轉移；銅鎢基板

並列摘要

In this study, the N-side up vertical light-emitting diodes (VLEDs) with 40 mil×40mil dimension were fabricated and the copper invar copper (CIC) substrate were used to bond to LEDs with wafer bonding technique. We replaced the original GaAs substrate with a CIC substrate by an epilayer -transfer technology, and solved various problems when using a CIC substrate, for example, the CIC substrate was damaged by an NH4(OH) solution, and photoresist was carbonized by ICP dry etching. We use gold-tin metals for wafer bonding. It was found that the bonding yield is more than 90% and the bowing of the wafer pair is about 21.48 μm for LED and CIC bonding., We try different annealing temperature which was 340, 350, 360, 370, 380 oC. It was found that the resistance obtained by annealing under N2 at 360 oC was the smallest, which is the Ohmic contact and the resistance is 96 ohms. Reliability was measured from lifetime measurement process to determine the ability to survive for 672 hours under wafer-bonding conditions. However, compared with the CuW LEDs and CIC substrate LEDs, the LEDs on CIC substrate have the highest saturation current with 900mA, which is superior to the CuW LEDs. The wavelength variation of LEDs on CIC substrate is also lower than that of Si substrate, with a variation of 0.02 nm/mA and the thermal resistance of 8.22 K/W. In view of the above, since the cost of the CuW substrate is much higher than that of the CIC substrate, and the variation in light-emitting wavelength of the LED made of the Si substrate is larger than that of the CIC substrate, this paper will use the LED made of the CIC substrate to discuss and use it on High-power LED industry.

並列關鍵字

CIC (copper invar copper), ； red light emitting diode ； wafer bonding ； epilayer transfer ； CuW substrate

參考文獻

[1] M. R. Krames, O. B. Shchekin, R. Mueller-Mach, L. Zhou, G. Harbers, and M. G. Craford, “Status and future of high-power light-emitting diodes for solid-state lighting”, J. Display Technol., vol. 3, pp. 160–175 (2007)

Google Scholar

[2] G. Harbers, S. Bierhuizen, and M. R. Krames, “Performance of high power light-emitting diodes in display applications”, J. Display Technol., vol. 3, pp. 98–109 (2007)