PECULIARITIES OF TIME-DEPENDENT-DIELECTRIC BREAKDOWN CHARACTERISTICS OF PURE AND DOPED TA2O5 STACKS

E. Atanassova, A. Paskaleva

Abstract: The effect of both the process-induced defects and the dopant on the time-dependent-dielectric breakdown in Ta₂O₅ stacks is discussed. The breakdown degradation is analyzed in terms of specific properties of high-k stacks which make their dielectric breakdown mechanism completely different from that of classical SiO₂. The relative impact of a number of factors constituting the reliability issues in Ta₂O₅-based capacitors (trapping in pre-existing traps, stress-induced new traps generation, the presence of interface layer at Si and the role of the dopant) is clarified.

Key words: high-k stack; doped Ta₂O₅; Weibull distribution; hard breakdown