Analysis and Remedy of the Discolor on Back-Side Revealing TSV

In this paper, the discolor on back-side revealing through-silicon-via (TSV) after wafer thinning and silicon recess process was investigated with various surface analysis methods. According to the analysis results, surface discolor could be raised by Cu oxidation during Si recess process. To eliminate the discolor occurrence, a remedy with in-situ Ar-ion bombardment was proposed which plays a role of enforced surface clean in the same plasma process stage. After this modified Si recess process, surface analysis were performed to ensure a comparable result to standard process but less Cu oxidation.