The role of nitrogen-related defects in high-k dielectric oxides: Density-functional studies
نویسندگان
چکیده
Using ab initio density-functional total energy and molecular-dynamics simulations, we study the effects of various forms of nitrogen postdeposition anneal sPDAd on the electric properties of hafnia in the context of its application as a gate dielectric in field-effect transistors. We consider the atomic structure and energetics of nitrogen-containing defects which can be formed during PDA in various N-based ambients: N2, N2 , N, NH3, NO, and N2O. We analyze the role of such defects in fixed charge accumulation, electron trapping, and in the growth of the interface SiO2 layer. We find that nitrogen anneal of the oxides leads to an effective immobilization of native defects such as oxygen vacancies and interstitial oxygen ions, which may inhibit the growth of a silica layer. However, nitrogen in any form is unlikely to significantly reduce the fixed charge in the dielectric. © 2005 American Institute of Physics. fDOI: 10.1063/1.1854210g
منابع مشابه
Density Functional Theory Simulations of High-k Oxides on III-V Semiconductors
Abstract A comprehensive overview of density functional theory simulations of high-k oxide/III-V semiconductor interfaces is presented. The methodologies of realistic amorphous high-k oxide generation by hybrid classical-DFT molecular dynamics are compared. The simulation techniques, oxide/semiconductor model designs and rules for formation of unpinned high-k oxide/semiconductor interfaces are ...
متن کاملDensity Functional Theory Studies of Defects in the (5,5) Silicon Nanotube
We have performed density functional theory (DFT) calculations to investigate the properties of defect in arepresentative armchair model of silicon nanotubes (SiNTs). To this aim, the structures of pristine and defective(5,5) SiNTs have been optimized and the properties such as bond lengths, total energies, binding energies,.formation energies, gap energies, and dipole moments have been evaluat...
متن کاملFIRST PRINCIPLES COMPUTATIONS Recent progress in ab initio simulations of hafnia-based gate stacks
The continuous size downscaling of complementary metal–oxide–semiconductor (CMOS) transistors has led to the replacement of SiO2 with a HfO2-based high dielectric constant (or high-k) oxide, and the polysilicon electrode with a metal gate. The approach to this technological evolution has spurred a plethora of fundamental research to address several pressing issues. This review focusses on the l...
متن کاملInfluence of Dielectric Constant on Codon-Anticodon pairing in mRNA and tRNA triplets by Theoretical Studies: Hartree-Fock and Density Functional Theory Calculations.
In this paper we have focused on the dielectric constant effect between various solvents with theoretical modelin the biochemical process. Thereby, AAA, UUU, AAG and UUC triplex sequences have been optimized inwater, methanol, ethanol and DMSO with proposed SCRF Model of theory. The solvation of biomolecules isimportant in molecular biology since numerous processes involve to interacting a prot...
متن کاملHigh dielectric constant oxides
The scaling of complementary metal oxide semiconductor (CMOS) transistors has led to the silicon dioxide layer used as a gate dielectric becoming so thin (1.4 nm) that its leakage current is too large. It is necessary to replace the SiO2 with a physically thicker layer of oxides of higher dielectric constant (κ) or ‘high K’ gate oxides such as hafnium oxide and hafnium silicate. Little was know...
متن کامل