Preparation and characterization of tantalum oxide films produced by reactive DC magnetron sputtering

Nanostructure characterization of high k materials by spectroscopic ellipsometry

“…1, typical of amorphous structures. This was also observed by other authors on films annealed below 500 8C, with crystallization occurring only at temperatures above 700 8C [14,15]. As the films are mainly amorphous, a simple Tauc-Lorentz (TL) dispersion is expected to fit the SE experimental data [11,16].…”

Multi-technique characterization of tantalum oxynitride films prepared by reactive direct current magnetron sputtering

“…The total pressure of 0.8 Pa was kept constant by regulating the Ar flow into the chamber, while systematically changing the O 2 and N 2 flow. In order to prepare TaO x N y films, we have started with 20 sccm O 2 flow, which corresponds to the oxidic mode sputtering of the Ta target [11]. Then, O 2 is partially replaced by N 2 .…”

“…The XRD measurements reveal that pure tantalum oxide films are amorphous (Fig. 5a) [11]. Upon increasing the nitrogen fraction in the reactive gas mixture there is no change in the amorphous structure of these films prepared as long as we maintain the N 2 flow below 16 sccm.…”

Redox Reactions at Cu,Ag/Ta2O5 Interfaces and the Effects of Ta2O5 Film Density on the Forming Process in Atomic Switch Structures

“…[ 8 ] Ag/Ta 2 O 5 -based, gapless-type atomic switches displayed conductance quantization, thus demonstrating the formation of a single point contact in a thin oxide fi lm, which is similar to what occurs in gap-type atomic switches. [ 9,10 ] Oxide fi lms formed by any physical vapor deposition method typically exhibit nanoporous structures, with densities lower than the bulk state, [ 11 ] which can absorb moisture from the ambient atmosphere. In previous work, we examined the switching characteristics of Cu/Ta 2 O 5 /Pt and Cu/SiO 2 /Pt cells as a function of ambient water vapor pressure.…”