以有机酸气氛进行铜表面改质之研究Surface modification of - YOKE.PDF

以有機酸氣氛進行銅表面改質之研究 Surface modification of Cu with organic acid vapors 2 *1 1 張智勛 宋振銘 蔡嘉航 Chih-Hsun Chang2 Jenn-Ming Song* 1 Chia-Hang Tsai1 1 2 國立中興大學材料科學與工程學系 國立東華大學材料科學與工程學系 NSC 101-2628-E-005-001-MY2 摘要 銅因具優良導電、導熱性質以及加工容易等諸多優點，在微電子線路及構裝 方面應用甚廣，但由於銅表面極為容易氧化，故如何潔淨銅表面一直是項重 要課題。本研究以有機酸蒸氣還原銅表面氧化物來達到銅表面潔淨目的，並 由電解拋光與檸檬酸溶液浸泡，進行比對。由UV-vis 與XPS 光譜分析可得知， 原試片表面存在Cu(OH) 、CuO 與Cu O ，經電解拋光、檸檬酸浸泡以及甲酸 2 2 蒸氣處理皆可使CuO 與Cu O 之吸收峰強度下降，但降低Cu(OH) 峰的效果 2 2 較不明顯。XPS 縱深成份分析顯示，未處理銅試片表面之氧含量在深度2 nm 深度時仍然超過 10 at% ，而分別經過電解拋光、檸檬酸或甲酸蒸氣處理後的 試片大多在深度0.5 nm 時氧含量可降至5 at%以下，表面碳污染亦可被清除。 由粗度量測結果可發現，電解拋光與檸檬酸兩種處理皆會使粗糙度下降，而 經甲酸氣氛處理試片表面粗糙度則未變動，顯示甲酸氣氛處理與其它兩者之 表面淨化運作方式並不相同。 關鍵字：有機酸、表面改質、UV-vis 、XPS Abstract Due to the excellent electrical and thermal conductivities, as well as superior ductility and manufacturability, copper has been widely used as interconnect materials. However, copper still possesses a notorious drawback of easy oxidation. Using carboxylic acid vapors, this study develops a vapor phase method for cleaning copper surface. Compared with commercial processes such as electro-polishing, chemical mechanical polishing and etching treatment by acid solution or plasma, the proposed process has great potential because neither wet process nor high vacuum are needed. According to the UV-visible spectra, Cu(OH) , CuO and Cu O can be detected on the 2 2 surface of as-received copper foils stored at ambient. The intensity of copper oxides could be significantly reduced subjected to electro-polishing, citric aci