Effect of Process Parameters on TSV Formation Using Deep Reactive Ion Etching

Abstract

In the development of 3D package, through sihcon via (TSV) formation technology by using deep reactive ion etchmg (DRIE) is one of the key processes We performed the Bosch process, which consists of sequentially alternating the etch and passivation steps using SF(6) with O(2) and C(4)F(8) plasma, respectively We investigated the effect of changing variables on vias the gas flow time, the ratio of O(2) gas, source and bias power, and process time Each parameter plays a critical role in obtaining a specified via profile Analysis of via profiles shows that the gas flow time is the most critical process parameter A high source power accelerated more etchant species fluorine ions toward the silicon wafer and improved their directionality With 02 gas addition, there is an optimized condition to form the desired vertical interconnection Overall, the etching rate decreased when the process time was longer