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A basic model is applied to the simulation of wet oxidation and the results are compared with dry oxidation.

Several first-principles calculations are conducted to explain the various size-dependent properties of the different ballistic silicon nanowire field effect transistors. The size dependent injection velocity of the system is shown to be completely dependent on the Fermi level.

Simultaneous diffusion of Si and B in thermally grown SiO2 is modeled considering the effect of SiO molecules at the Si/SiO2 interface and diffusing into SiO2 to enhance both Si and B diffusion. Results indicate that Si and B diffusion in SiO2 are correlated via SiO molecules.

Self-diffusion coefficients of Si in thermally grown SiO2, on a semiconductor-grade silicon wafer are determined at temperatures between 1150 and 1300 degree centigrade under equilibrium conditions using isotope heterostructures ((super nat)SiO2/(super 28)SiO2). The diffusion coefficients determined agree very well with those of the values of Si self-diffusion in fused silica under equilibrium conditions.

We report on the electronic roles in filamentary-type switching of binary oxide-based resistive random access memories using ab initio calculations. We show that charge injection and removal determine the thermodynamic stability of the vacancy filament and the diffusion in the memory devices; electron injection induces the vacancy cohesion that stabilizes the filament, whereas removal of these electrons favors the vacancy isolation that destabilizes the filament; electron removal makes the energy barrier of the vacancy diffusion processes small enough to be overcome by joule heating. The vacancy cohesion-isolation processes are induced by charge injection and removal that leads to occupation of the bonding-like electron states, which can be controlled by shifting the system Fermi level via an applied voltage during memory operation. The vacancy cohesion-isolation phase transition upon charge injection and removal is thus one of the main factors that govern resistive switching. Based on the physics, we propose three-layer stack structures for further improvement of the memory characteristics. [ABSTRACT FROM AUTHOR]

We have theoretically shown that doping of N atoms increases the dielectric constant of the Hf silicates, enhancing both the electronic and lattice polarization contributions. The enhancement of the lattice contribution is dominant and is attributed to low-frequency vibration modes induced by the N doping. It is found that Hf and Si ions bonded to N atoms located at O vacancies largely vibrate in the modes and play a crucial role in the enhancement. Doped N atoms are shown to also improve the electric characteristic of the silicates, elevating O vacancy levels appearing in the band gap of the silicates. [ABSTRACT FROM AUTHOR]

Self-diffusion of Si in thermally grown SiO[sub 2] is modeled taking into account the effect of SiO molecules generated at the Si/SiO[sub 2] interface and diffusing into SiO[sub 2] to enhance the self-diffusion. Based on the model, a recent self-diffusion experiment of ion-implanted [sup 30]Si in SiO[sub 2], which showed increasing self-diffusivity with decreasing distance between the [sup 30]Si diffusers and Si/SiO[sub 2] interface [Fukatsu et al., Appl. Phys. Lett. 83, 3897 (2003)], was simulated, and the simulated results fit the experimental profiles. Furthermore, the simulation predicts that the self-diffusivity would increase for a longer annealing time because more SiO molecules should be arriving from the interface. Such time-dependent diffusivity was indeed found in our follow-up experiments, and the profiles were also fitted by the simulation using a single set of parameters. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]