Reactivity Research of Hydrogen Peroxide and Copper Ions at Electrochemical Plating Process

• Main Authors: WangCheng-Shyan, 王承賢
• Other Authors: Kuen-Chyr Lee
• Format: Others
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/31890527877610112312

碩士 === 崑山科技大學 === 環境工程研究所 === 93 === The usage of hydrogen peroxide and copper ions were increased with the mass production of the copper integration process for improving the devices performance in semiconductor industry. The compatibility of hydrogen peroxide and copper ions at electrochemical plating process was studied under various concentrations of copper ions, hydrogen peroxide, sulfate ions, chloride ions, additives and solution pH values. The root causes of explosion of waste ECP chemicals drum tank were identified by integration of this research results, process recipes and hardware configuration. Experimental results demonstrated that the heat generation rate was decreased in more acidic solution conditions which repressed the generation of Cu2+(HO2－) ions at CuSO4/H2O2 system. The concentrations of Cu2+(HO2－) ion could be enhanced by the addition of chloride ions. And cuprous ions might not just react with hydroxyl free radical but partly react with hydrogen peroxide to generate heat source which resulted from hydroxyl free radical was partly scavenged by chloride ions. Consequently, the TMR (Time to Maximum Rate) was found to be decreased significantly with increasing chloride ion concentrations at CuSO4/H2O2/Chloride system. The heat generation rate in lower concentration of citrate ions was larger than that without the chelating agent additions. These might be because hydroxyl free radical was scavenged by organic species like as citrate ions, and then changed the parts of reaction ways of cuprous ion at CuSO4/H2O2/citrate system. The TMR at CuSO4/H2O2/citrate system was lower than that at CuSO4/H2O2/EDTA system due to copper-EDTA complex ion with higher stability constant to reduce the concentrations of Cu2+(HO2－) ions. The behaviors of heat generation could be explained by introducing the concepts of species distribution and free radical reaction mechanisms in aqueous solution at CuSO4/H2O2/additive system.