利用選擇性電鍍法製備銅凸塊於矽基板之研究

The Study of the Selective Electroplating of Cu Bumps on Si Substrate

陳洛嶙(Lo-Lin Chen)

指導教授 ： 許世杰

淡江大學/工學院/化學工程與材料工程學系碩士班/碩士(2014年)

https://doi.org/10.6846/TKU.2014.00580

摘要

本論文旨在開發選擇性電鍍的製程技術，此技術能夠不需要任何阻擋層，而達到在半導體基板預先晶粒定義的位置上電鍍銅凸塊的目的。
研究中，使用定電流密度之方法，可以成功地製作出不需阻擋層的圖形化電鍍銅凸塊，而達到選擇性電鍍的效果。以表面輪廓儀測量電鍍銅凸塊的輪廓，可觀察到電鍍銅凸塊的平均厚度會隨著電流密度增加而降低，而電鍍銅凸塊的邊緣會隨著電流密度增加有明顯的突起。進一步地研究發現，電流密度為45 mA/cm2時為形貌轉換過渡期，此時銅凸塊部分邊緣有稍微突起之現象；電流密度為45 mA/cm2以下時，銅凸塊形貌為蘑菇頭狀；而當電流密度為45 mA/cm2以上時，銅凸塊邊緣則明顯突起。這個現象將藉由邊緣效應及電荷聚集效應的機制作一深入之探討。此外，本研究也定義了相似度來判定銅凸塊的形貌狀況，從實驗結果中可以得知當電流密度為50 mA/cm2時，電鍍銅凸塊基板有最適化的表面形貌。
除了定電流密度之外，本研究還完成了定電位、脈衝電流的測試實驗，由於僅為初期之實驗結果，故放入附錄中以供參考。

關鍵字

選擇性電鍍 ； 銅凸塊 ； 電流密度 ； 半導體

並列摘要

The purpose of the study is developing the selective electroplating technique. For the manufacture of semiconductor, we can successfully fabricate the copper bumps on the pre-defined pattern seed layer without using barriers by the selective electroplating technique.
In the study, we can successfully fabricate the copper bumps by using galvanostatic methods. The contours of the copper bumps were measured by the Alpha-step profilometer. The thickness of the copper bumps decreases with increasing current density. In further investigations, it is found that the copper bumps with obtuse edges obtained if the electroplating current density is lower than 45 mA/cm2. At the current density of 45 mA/cm2, a portion of the edge of the copper bumps was slightly protruded as the transition stage. The edge of the copper bumps was obviously protruded when deposited using current density higher than 45 mA/cm2. It further discusses with edge effect and charge aggregation effect. In addition, the morphology and the similarity of the copper bumps at 50 mA/cm2 are the best from the results.

並列關鍵字

selective electroplating ； Cu bump ； current density ； semiconductor

參考文獻

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