Redistribution layer (RDL) process development and improvement for 3D interposer

RDL process becomes more and more important with through Si interposer (TSI) application in 3D packaging. RDL line/space needs to be shrinking with the increasing of device density. We had been developed low temperature (LT) damascene process for the RDL formation in 3D interposer integration. The sample failed at thermal reliability test. High temperature (HT) RDL was developed and demonstrated after TSV annealing temperature optimization in this paper.