Analysis of TDDB lifetime projection in low thermal budget HfO2/SiO2 stacks for sequential 3D integrations

We study the impact of fabrication thermal budget on stress-induced defect generation in HfO 2 /SiO 2 stacks compatible with novel Sequential 3D integration. By using stress-induced leakage current (SILC) spectroscopy we show that gate stacks fabricated at low thermal budget, compatible with top-tier integration have a significant pre-existing defect density. We use breakdown and successive breakdown statistics to estimate the number of percolation paths at time zero as a function of the area. Finally, we introduce a modified all-in-one reliability plot that incorporates the impact of the pre-existing defect density on lifetime projection.