Applying Uniform Design of Experiment in Tri-Layer-Based Trench Etch for EM Lifetime Performance Enhancement

Abstract

In this paper, we studied the improvement of EM lifetime distribution including both intrinsic lifetime extension and the reduction of earlier failure percentage by applying a uniform design of experiments (UDE) to organic under layer (OUL) step. UDE is an experimental approach that is capable of distributing experiments evenly within experimental space, especially when a large number of experimental levels are required. In our case, the experiments were carried out with a six variable design table of OUL step’s important parameters including pressure, power, gas flow rate and over-etch percentage. Factor level varies from four to six for each variable based on previous silicon wafer learning. The optimal OUL condition was identified among the EM performance of 18 UDE pi-runs by means of statistically scientific analysis. The predicted condition was validated and shows the current-best EM performance from the point of view of EM lifetime and the earlier failure percentage.