Title :
Density functional theory analysis of SiO2-oxynitride interfaces
Author :
Stefanou, Athanasios
Author_Institution :
Dept. of Electr. Eng., ESAT K. U. Leuven, Leuven, Belgium
Abstract :
Two different interface models for crystalline oxynitride on SiO2 are proposed and investigated. The two models are proposed to model oxynitride gate stacks on Si substrate with SiO2 as the interlayer film. State-free insulating interfaces were obtained by expanding the bulk oxynitride cell by approximately 12% and 1% to match the lattice constant of SiO2 along the [100] and [010] axis respectively. The results that were obtained demonstrate state-free insulating interfaces for the two models with, however, valence band offsets of 0.1eV and 1.45 eV respectively. The significant decrease in the valence band offsets is attributed mainly to the significant expansion of the oxynitride´s lattice constant to lattice-match (001)SiO2, as well as, to the high concentration of nitrogen atoms in the interface.
Keywords :
density functional theory; dielectric materials; interface structure; lattice constants; silicon compounds; valence bands; Si; SiO2-Si2N2O; [010] axis; [100] axis; bulk oxynitride cell; crystalline oxynitride; density functional theory; interface models; interlayer film; lattice constant; nitrogen atoms; oxynitride gate stacks; silicon dioxide-oxynitride interfaces; silicon substrate; state-free insulating interfaces; valence band offsets; Atomic layer deposition; CMOS technology; Density functional theory; Dielectric devices; High K dielectric materials; High-K gate dielectrics; Insulation; Lattices; Nitrogen; Silicon;
Conference_Titel :
Nanotechnology, 2009. IEEE-NANO 2009. 9th IEEE Conference on
Conference_Location :
Genoa
Print_ISBN :
978-1-4244-4832-6
Electronic_ISBN :
1944-9399
