化學-機械拋光法在積體電路多層金屬內連接線平坦化製程中扮演重要角色；而銅的導電性佳，抵抗電子遷移的能力好，使得銅成為半導體製程中取代鋁的新一代導電材料。影響銅的平坦化的因素以及平坦化的機制，乃成為熱門的研究課題。
本研究中則主要針對化學-機械拋光過程中電化學反應加以研究，特別是以銅在含不同氧化劑的研磨液中之電化學行為作為研究的重點。為了模擬研磨液在化學機械拋光過程中流動的特性，以銅旋轉電極為工作電極，來探討氧化劑種類、濃度及轉速對銅在0.0078 M檸檬酸水溶液中之電化學性質的影響。實驗結果顯示，在靜止狀態下，以雙氧水為氧化劑時，腐蝕電位隨著雙氧水濃度的增加而上升，其溶解速率在含6 vol. %雙氧水之0.0078 M檸檬酸水溶液中有極大值。且以雙氧水為氧化劑時，氧化銅及氫氧化銅會在銅表面生成；若以硝酸鐵為氧化劑時，腐蝕電位及溶解速率皆會隨著硝酸鐵濃度的增加而上升。另由表面型態觀察可知，在0.0078 M檸檬酸水溶液中表面呈現高低相間規則而平行之波浪狀；而在含雙氧水的0.0078 M檸檬酸水溶液中，表面形狀變為平滑；若在添加硝酸鐵之0.0078 M檸檬酸水溶液中，表面高低相間的規則狀消失，並可發現凹洞存在。
旋轉狀態下，以雙氧水為氧化劑時，腐蝕電位隨著轉速的增加而呈下降的趨勢，而溶解速率在添加雙氧水濃度為2 vol. % 時會有極大值。另由表面分析結果可知，含雙氧水之0.0078 M檸檬酸水溶液中，在三種轉速條件下( 100、1000、3000 rpm )，氧化銅及氫氧化銅仍然會在銅的表面附著。當以硝酸鐵為氧化劑時，腐蝕電位及溶解速率皆隨著轉速的增加而上升。

Chemical mechanical polishing (CMP) is one of the crucial techniques under intensive investigation for Ultra-Large-Scale- Integration (ULSI). Owing to the low electrical resistivity and high electromigration resistance, copper has emerged as alternative choice for aluminum in the applications of the interconnect in the future.
In this study, the electrochemical properties of copper in citric acid were investigated, with special emphasis on the effect of oxidizing agent. In order to simulate the flow condition of slurry during chemical mechanical polishing, a rotating electrode was employed. The effects of rotation, types and concentrations of oxidizing agent on the electrochemical behavior of copper were investigated. The oxidizing agents used were hydrogen peroxide and iron nitrate. The rotating speed was controlled in the range of 0~3000 rpm.
Under static condition, the corrosion potential of copper increased with increasing concentration, and the dissolution rate increased with the concentration of hydrogen peroxide in the range of 0~6 vol.%, while it decreased beyond 6 vol. %. With iron nitrate as the oxidizing agent, both the corrosion potential and the dissolution rate were increased with its concentration in the range of 0~0.2 M. Examination of surface morphology using atomic force microscope (AFM) revealed that the addition of hydrogen peroxide and iron nitrate could cause the morphology of copper become more smooth in 0.0078 M citric acid.
Under rotating condition, the corrosion potential of copper decreased with increasing in 0.0078 M citric acid solution with hydrogen peroxide addition. The dissolution rate was found to increase with increasing rotating speed in 0.0078 M citric acid solution added with hydrogen peroxide. However, with iron nitrate addition, both of the corrosion potential and the dissolution rate of copper increased with the rotating speed in 0.0078 M citric acid

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