Berlin 2012 – wissenschaftliches Programm
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DF: Fachverband Dielektrische Festkörper
DF 13: Poster II
DF 13.5: Poster
Mittwoch, 28. März 2012, 15:00–17:30, Poster E
Oxygen Related Defects and the Reliability of High-κ Dielectric Films in Field Effect Transistors: An Investigation beyond Density Functional Theory — •Ebrahim Nadimi1,2, Rolf Öttking2, Philipp Plänitz2, Martin Trentzsch3, Torben Kelwing3, Rick Carter3, Christian Radehaus2, and Michael Schreiber1 — 1Institut für Physik, Technische Universität Chemnitz, D-09107, Chemnitz Deutschland — 2GWT-TUD GmbH Geschäftsstelle Chemnitz, Annaberger Str. 240, 09125 Chemnitz, Deutschland — 3Global Foundries, D-01109, Dresden Deutschland
The introduction of high-κ (HK) gate dielectrics and metal gate in silicon field effect transistors has created many challenges amongst others the reliability of the gate dielectric. Bias temperature instability (BTI) and stress induced leakage current (SILC) are the key degradation characteristics. The community agrees about the important role of oxygen related defects in the degradation process of HK dielectrics. In this work, ab initio methods are applied to investigate oxygen vacancies as the most important defects in Hf-based dielectrics. Atomic structure, formation energy and electronic structure of these defects are investigated at the level beyond density functional theory using the exact-exchange hybrid functional. We also propose a defect generation mechanism, which could explain the relatively low defect activation energies obtained experimentally. The passivation of the oxygen vacancies by means of different dopants is also investigated and the results are compared. This work was supported by the Sächsische AufbauBank under HEIKO project Grant No. 1000648806/626.