High-k dielectrics breakdown accurate lifetime assessment methodology
High-k gate dielectrics, particularly Hf-based materials, are likely to be implemented in CMOS advanced technologies. One of the important challenges in integrating these materials is to achieve lifetimes equal or better than their SiO/sub 2/ counterparts. The reliability of high-k structures is influenced both by the interfacial layer as well as the high-k layer. In this paper, we propose an accurate statistical analysis of the breakdown linking the progressive breakdown to the breakdown of the interfacial layer and the soft breakdown or hard breakdown to the high-k layer breakdown. The breakdown of the two layers are found to be independent. Based on this analysis, we study the degradation mechanisms and we demonstrate that the multi vibrational hydrogen release (MVHR) process is the prevalent mechanism which drives the creation of a percolation path through the interfacial layer.