Effects of electrolyte towards copper wire metallurgical interconnection in semiconductor

Abstract

Abstract Copper (Cu) wire has been extensively used in the semiconductors industry to replace gold wire because of its cost-effectiveness and high performance. However, it has a massive challenge because of its high oxidation rate, high hardness, and high susceptibility to corrosion which is time-sensitive under environmental conditions. One of the attractive factors to investigate is the electrolytes used in the assembly process of copper wire. However, these electrolyte chemicals may potentially affect the quality of the copper wire bond’s metallurgical interconnection, manifesting as copper corrosion. Therefore, this paper will investigate the mechanism of the electrolyte reaction and the chemicals. In addition, the metallurgical morphology of the copper wire observes through electron microscopy. The results suggest that corrosion occurs with a specific time rate, electrolyte type-dependent and metallurgical interconnection system. The Copper wire bonded on silver (Ag) plated lead frame (Cu-Ag-Cu) interconnection experiences a significant morphological change in most compared with other electrolyte systems. Furthermore, since it is a bimetallic element (Cu and Ag) thus, the corrosion type is galvanic.