Modeling of Diffusion and Incorporation of Interstitial Oxygen Ions at the TiN/SiO₂ Interface

Abstract

Silica based Resistive Random Access Memory (ReRAM) devices have become an active research area due to complementary metal-oxide-semiconductor (CMOS) compatibility and recent dramatic increases in their performance and endurance. In spite of both experimental and theoretical insights gained into the electroforming process,

Controlling the TiN Electrode Work Function at the Atomistic Level: A First Principles Investigation

“…The metal-insulator-metal (MIM) integrated capacitors are key device structures for modern analog and radio frequency integrated circuits [1]. This includes both two-terminal devices such as in ovonic selectors [2], [3], and layered gates in connection with high-κ metal-oxide dielectrics, such as, HfO 2 [4], TiO 2 [5], SiO 2 [6], [7], and Al 2 O 3 [8]. In this scenario, TiN recently become the reference metal for CMOS compatible gates and MIM devices [9].…”

Structure, Oxygen Content and Electric Properties of Titanium Nitride Electrodes in TiNx/La:HfO2/TiNx Stacks Grown by PEALD on SiO2/Si

“…Cottom et al [ 29 ] in their theoretical study of the atomistic mechanism of oxygen migration to the interface between amorphous SiO 2 and polycrystalline TiNx, they have shown that the arrival of oxygen atoms at the interface is accompanied by preferential oxidation of undercoordinated Ti sites at the interface, forming a Ti−O layer. Molecular dynamics and spin-polarized density functional theory calculations demonstrate the preferential incorporation of oxygen at defects within the TiN x grain boundaries and their fast diffusion along them.…”

“…N vacancies can affect the oxygen diffusion mechanism. It was proposed that the oxygen migrates and occupies the N vacancy site where it is then trapped due to the high energy barrier to be overcome to leave the vacancy site, i.e., 2.0 eV [ 29 ]. In the MIM structures studied, the numerous grain boundaries in the top/bottom electrodes significantly facilitate oxygen diffusion throughout the thickness of TiN x layers, and the nitrogen-vacancy sites trap oxygen.…”

“…This provides evidence that at least a large part of the oxygen stems from the neighboring oxide layers, and diffusion should be considered as a pathway for the formation of titanium oxynitride. Diffusion inside the TiN x layer enhanced by intergranular boundaries in its columnar structure has been reported [ 27 , 28 , 29 ] but does not explain oxygen availability. Therefore, the actual mechanism of this diffusion still needs more investigation.…”

Adsorption and Surface Diffusion of Atomic Ru on TiN and SiO2: A First-Principles Study

“…Therefore, the surface diffusion rate, as well as its behavior, obviously depends on the substrate materials and their surface preparation conditions [23]. Atomistic simulations based on first-principles calculations are often shown to be powerful in estimating the diffusion coefficients [24,25], as recent studies on technologically important surfaces such as TiN and SiO 2 have shown [26][27][28][29][30][31][32][33][34][35][36][37].…”