DocumentCode :
269710
Title :
The Degradation Process of High- 
Gate-Stacks: A Combined Experimental and First Principles Investigation
Author :
Nadimi, Ebrahim ; Roll, Guntrade ; Kupke, Steve ; Öttking, Rolf ; Plänitz, Philipp ; Radehaus, Christian ; Schreiber, Michael ; Agaiby, Rimoon ; Trentzsch, Martin ; Knebel, Steve ; Slesazeck, Stefan ; Mikolajick, Thomas
Author_Institution :
Electr. Eng. Dept., K.N. Toosi Univ. of Technol., Tehran, Iran
Volume :
61
Issue :
5
fYear :
2014
fDate :
May-14
Firstpage :
1278
Lastpage :
1283
Abstract :
Theoretical and experimental methods are applied to investigate the degradation of SiO2/HfO2 gate-stacks in state-of-the-art MOSFETs. A combination of density functional theory and nonequilibrium Green´s function formalism has been applied to the atomic scale calculation of the leakage current through SiO2/HfO2 dielectrics. Samples with different dielectric stacks have been taken into account to study the thickness dependence of SiO2 and HfO2 on the leakage current. The calculated results show a good agreement with the leakage current and constant voltage stress measurements. The current influenced by oxygen vacancies, particularly in the high-k dielectric close to the SiO2/HfO2 interface has been analyzed. Comparison between the measurement and simulation results show that oxygen vacancy defects in the HfO2 are a likely cause for progressive stress-induced leakage current in MOSFETs with ultrathin high-k gate-stack.
Keywords :
Green´s function methods; MOSFET; density functional theory; hafnium compounds; high-k dielectric thin films; leakage currents; silicon compounds; vacancies (crystal); MOSFET; SiO2-HfO2; atomic scale calculation; constant voltage stress measurements; density functional theory; dielectric stacks; high-k dielectric; high-k gate-stack; nonequilibrium Green function formalism; oxygen vacancy defects; stress-induced leakage current; Dielectrics; Hafnium compounds; High K dielectric materials; Leakage currents; Logic gates; Silicon; Stress; Density functional theory (DFT); MOSFETs; high- $k$; high-k; leakage current; nonequilibrium Green´s function (NEGF); oxygen vacancies; stress-induced leakage current (SILC); stress-induced leakage current (SILC).;
fLanguage :
English
Journal_Title :
Electron Devices, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9383
Type :
jour
DOI :
10.1109/TED.2014.2313229
Filename :
6782397
Link To Document :
