由於銅本身具有良好的導電度，以及優越的抗電子遷移的能力，因此使用銅做為半導體元件可以有效的降低RC Delay的效應，使得銅的鑲鉗式製程近年來受到注目。而化學機械拋光(CMP)技術已被廣泛應用於鑲鉗式製程的表面平坦化處理，主要作用是移除鑲鉗後表面不平坦的銅膜和擴散阻隔層間的階差。
一般的CMP製程主要包含兩個階段，第一階段是僅快速、整體的移除多餘的銅膜，第二階段是將整個表面包括氧化層、擴散阻隔層與銅膜一起移除。而研磨液中添加的研磨砥粒在第一階段的研磨過程中，常會造成銅表面的刮傷，影響元件的良率。
銅無砥粒研磨(AFP)技術是一個有希望可以取代一般CMP技術的新製程。它可以使在移除低應力材料的表面時，避免研磨砥粒造成的刮傷破壞。在以Benzotriazole(BTA)當做抑制劑及硝酸作為氧化劑混合的漿料，進行Cu-AFP的實驗中，由於Cu-BTA鈍化膜的形成，使得我們可以得到一個高平坦度的表面。然而卻無法避免明顯的Pattern Effect。
在本實驗中將與BTA具有相似分子結構的衍生物，用來取代BTA做為銅腐蝕抑制劑，研究不同的分子結構對表面鈍化膜性質的影響，以減低研磨中的Pattern Effect。而由實驗中電化學分析的結果中發現，5-Methyl-1H-benzotriazole 可以在銅面形成有效的鈍化膜抑制硝酸的腐蝕，而以1E-4M 5-Methyl-1H-benzotriazole 和1.1M的硝酸混合漿料進行AFP的結果發現，5-Methyl-1H-benzotriazole比BTA更能有效的抵抗Pattern Effect的效應。詳細的部份在論文中有更深入的討論。

The attractiveness of Cu dual damascene technology arises from a lower resistance capacitance (RC) delay due to higher electrical conductivity of Cu and its superior electro-migration performance. The damascene process eliminates residual metal by using chemical mechanical polishing (CMP) for field Cu and barrier removal.
Standard Cu CMP process involves two steps; step one involves polishing of Cu and stopping on the barrier layer, and step two requires removal of the barrier layer and planarization of the entire surface (Cu/Barrier/Ox). Additive abrasives in slurry sometimes scratched the surface in step one.
Abrasive free polishing (AFP) technology is one of promising alternatives for low-stress material removal to avoid scratching or film peeling during polishing. While Benzotriazole (BTA) as an inhibitor formulated with nitric acid (HNO3) as an oxidizer for Cu AFP process, it can provide high planarization efficiency based on formation of a strong BTA-Cu surface passivation during polishing, but in trade of low removal rates and large pattern-dependent planarization effect. In this study, the BTA derivatives such like (Benzotriazole-5-carboxylic acid, 5-Methyl-1H-benzotriazole) are investigated for reduced packing density of planar BTA-Cu complex compound for improving removal rate and pattern effect.
In this study, HNO3 fixed at 1.11M functions as oxidizer for Cu removal and BTA derivatives (Benzotriazole-5-carboxylic acid, 5-Methyl-1H-benzotriazole) chemistry as a corrosion inhibitor by forming a surface passivation on Cu surface. Electrochemical AC impedance technique was carried out to investigate surface passivation, which would be related to planarization. Furthermore, contact angle measurement’s results show the wetting effect and packing condition of a surface passivation formed during polishing. The planarization efficiency at various feature size of Cu interconnects with BTA derivatives(Benzotriazole-5-carboxylic acid, 5-Methyl-1H-benzotriazole) as inhibitors during Cu AFP are also discussed.

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