Title :
Comparison of tunnel currents through SiO2, HfO2, Ta2O5, ZrO2 and Dy2O3 dielectrics in MOS devices for ultra large scale integration using first principle calculations
Author :
Chakraverty, Mayank ; Kittur, Harish M.
Author_Institution :
IBM India Private Ltd., Bangalore, India
Abstract :
The work presented in this paper focuses on the effects of high leakage current in field effect transistors and the possible ways to play down with the leakage currents. This paper combines density functional theory and non equilibrium Green´s function formalism to perform atomic scale calculation of tunnel currents through SiO2, HfO2, Ta2O5ZrO2 and DY2O3 dielectrics in MOSFETs. The tunnel currents for different bias voltages applied to Si/Insulator/Si systems have been obtained along with tunnel conductance v/s bias voltage plots for each system and the plots have been analyzed with reference to the presently used bulk Si/SiO2/Si systems that have SiO2 as the gate dielectric material. The results justify the use of high dielectric constant materials as gate dielectric in FET devices so as to enable further downscaling of MOSFETs with reduced gate leakage currents thereby enabling ultra large scale integration.
Keywords :
Green´s function methods; MOS integrated circuits; ULSI; dysprosium compounds; hafnium compounds; leakage currents; oxygen compounds; silicon compounds; tantalum compounds; zirconium compounds; MOS devices; MOSFET; atomic scale calculation; bias voltage plots; bias voltages; density functional theory; dysprosium oxide dielectric; field effect transistors; first principle calculations; gate dielectric material; hafnium oxide dielectric; high leakage current; non equilibrium Green´s function formalism; silicon dioxide dielectric; silicon-insulator-silicon systems; tantalum pentoxide dielectric; tunnel conductance; tunnel currents; ultra large scale integration; zirconium dioxide dielectric; Dielectrics; Insulators; Leakage currents; Logic gates; MOSFET; Silicon; CMOS; Gate Leakage current; MOSFETS; drive current; threshold voltage; transconductance; tunnel current;
Conference_Titel :
Emerging Research Areas and 2013 International Conference on Microelectronics, Communications and Renewable Energy (AICERA/ICMiCR), 2013 Annual International Conference on
Conference_Location :
Kanjirapally
Print_ISBN :
978-1-4673-5150-8
DOI :
10.1109/AICERA-ICMiCR.2013.6575936