碳化矽薄膜對鋁基金錫共晶接合面之影響

Effect of Silicon Carbide Thin Film on Al-Based AuSn Eutectic Bonding Joint

楊詠鈞(Yung-Chun Yang)

指導教授 ： 陳文瑞

國立虎尾科技大學/電機資訊學院/光電與材料科技研究所/碩士(2014年)

摘要

本論文研究動機是參考DLC的概念應用於LED的覆晶封裝上，嘗試在鋁基底部濺鍍沉積上碳化矽來探討對鋁基金錫共晶接合結構上的影響。因為鋁無法進行電鍍等製程，因此將鋁表面先進行鋅置換與無電鍍鎳後，再以電鍍製備金錫堆疊層。在實驗過程中發現到，因碳化矽與鋁的熱膨脹系數差距過大，所以導致在進行熱壓合時，經過升、降溫後，會有薄膜剝離的狀況，使得元件的可靠度降低。後再參考以碳化矽作為基材的LED結構，嘗試在碳化矽上方先濺鍍沉積一層薄氮化鋁再濺鍍沉積鋁薄膜，因為碳化矽與氮化鋁不但熱膨脹係數接近，晶格常數也相當接近，而鋁與氮化鋁的晶格也較為匹配，並由實驗印證，薄膜附著力得以提升，剝離的狀況已大幅的改善，故將以此結構去探討對金錫共晶溫度與剪應力的關係，並找出最佳的共晶溫度，去做SEM、EDX、XRD分析，確認較佳的合金相，再將此參數以黃光微影方式開出圖形，並以LED作覆晶封裝，進行電性量測分析。

關鍵字

濺鍍沉積 ； 碳化矽 ； 熱膨脹係數 ； 金錫 ； 共晶接合 ； 覆晶封裝

並列摘要

In this study, the motivation is for the reference of DLC structure, silicon carbide deposited before aluminum film to discussing its effect of the Al-Base AuSn eutectic bonding joint structure. Because Al surface can’t electroplate direct, so first used Zn replaced the surface of Al, and deposited Ni by electroless Nickel. Then the Au/Sn stack-layer were electroplated on the metal. In the experiment ,we can observe the film will pilling after the thermal bonding process. According to the literature, this may be attributed to the Coefficient of thermal expansion different too large. We refer to the LED structure of using SiC-base, deposited the thin AlN film after deposited SiC film. Because the lattice constant and Coefficient of thermal expansion of SiC and AlN is nearly, then the lattice constant of Al and AlN also near match. After the experiment, the film adhesion of new structure is better than the old, film not pilling after bonding process. So this study using the metal sub-layer to explore the Au/Sn better alloy temperature on the Al-base. Structural characterizations were performed by SEM, EDX, and XRD. Finally, the lithography was utilized on glass substrates, after stack-layer completed, combined the LED by flip-chip to measure and analysis Electrical characteristics.

並列關鍵字

sputter deposited ； silicon carbide ； coefficient of thermal expansion ； AuSn alloy ； eutectic bonding ； flip-chip package

參考文獻

[5]Pin J. Wang et al., “Fluxless Bonding of Silicon Chips to Ceramic Packages Using Electroplated Au/Sn/Au Structure”, IEEE Advanced Packaging Materials Symposium, 2007.

[6]Jian Cai et al., “Microstructure of AuSn Wafer Bonding for RF-MEMS Packaging”, 6th International Conference on Electronic Packaging Technology, 2005.

[8] Jeong-Won Yoon et al., “Microstructural evolution of Sn-rich Au–Sn/Ni flip-chip solder joints under high temperature storage testing conditions”, Scripta Materialia, 56, pp. 661-664, 2007.

[9]Jeong-Won Yoon et al., “Reliability evaluation of Au–20Sn flip chip solder bump fabricated by sequential electroplating method with Sn and Au”, Materials Science and Engineering, 473, pp.119–125, 2008.

[11]Bhatnagar, M. et al., “Comparison of 6H-SiC, 3C-SiC, and Si for power devices”, IEEE Transactions on Electron Devices, VOL. 40, NO. 3 , 1993.