Estimation of fixed charge densities in hafnium-silicate gate dielectrics
Kaushik, Vidya S × O'Sullivan, Barry J Pourtois, Geoffrey Van Hoornick, Nausikaa Delabie, Annelies Van Elshocht, Sven Deweerd, Wim Schram, Tom Pantisano, Luigi Rohr, Erika Ragnarsson, Lars-Ake De Gendt, Stefan Heyns, Marc #
Ieee-inst electrical electronics engineers inc
IEEE Transactions on electron devices vol:53 issue:10 pages:2627-2633
In this paper, an effective technique and methodology for the estimation of fixed charge components in high-k stacks was demonstrated by varying both the SiO2 and high-k dielectric thicknesses. The SiO2 thickness was scaled on a single wafer by uniformly changing the etch time of a thermally grown SiO2 layer across the wafer. This minimized wafer-to-wafer variations and enables acquisition of statistically significant datasets. Layers with different thickness of both the nitrided and non-nitrided hafnium-silicate layers were then grown on these wafers to estimate all the interfacial and bulk charge components. The reproducibility and validity of this technique were demonstrated, and this method was used to compare the fixed charge levels in Hf-silicates (HfsiO) and nitrided-Hf-silicate (HfSiON) layers.