The structure‐driven properties of vanadium oxide have inspired enormous developments in the last decades, especially as a smart material for energy, sensors, and optoelectronics. The large variety of stable and metastable structures of vanadium oxide is discussed, based on the calculated formation energies and a broad overview of their structure‐related properties. The established chemical deposition processes from the gas phase are reviewed with a particular emphasis on the implemented precursors and the obtained vanadium oxide phases. Although a significant fraction of relevant vanadium oxide compounds is achieved by these methods, there are still rewarding challenges related to their controlled elaboration and the investigation of their responsive properties.
aMetal organic chemical vapor deposition is carefully optimized for the growth of pure CuCrO 2 delafossite coatings on glass substrates. The pulsed direct liquid delivery is demonstrated to be an efficient process technology for the controlled supply of the precursor solution in the evaporation chamber, which is shown to be one of the main process parameters to tailor the thin-film properties.We investigated the influence of the precursor concentration ratio Cu(thd) 2 (bis[2,2,6,6-tetramethyl-3,5-heptanedionato]copper(II)) and Cr(thd) 3 (tris[2,2,6,6-tetramethyl-3,5-heptanedionato]chromium(III)) on the crystal structure, morphology and electrical conductivity, at a reduced temperature of 370 1C. We observe for a low ratio, a pure delafossite phase with a constant Cu-poor/Cr-rich chemical composition, while at a high ratio a mixture of copper oxides and CuCrO 2 was found. The as-grown 140 nm-thick pure delafossite films exhibit an exceptional high electrical conductivity for a non-intentionally doped CuCrO 2 ,
S cm
À1, and a near 50% transparency in the visible spectral range.
A novel CMOS device architecture called silicon on nothing (SON) is proposed, which allows extremely thin (in the order of a few nanometers) buried dielectrics and silicon films to be fabricated with high resolution and uniformity guarantied by epitaxial process. The SON process allows the buried dielectric (which may be an oxide but also an air gap) to be fabricated locally in dedicated parts of the chip, which may present advantages in terms of cost and facility of system-on-chip integration. The SON stack itself is physically confined to the under-gate-plus-spacer area of a device, thus enabling extremely shallow and highly doped extensions, while leaving the HDD (highly doped drain) junctions comfortably deep. Therefore, SON embodies the ideal device architecture taking the best elements from both bulk and SOI and getting rid of their drawbacks. According to simulation results, SON enables excellent Ion/Ioff trade-off, suppressed self-heating, low S/D series resistance, close to ideal subthreshold slope, and high immunity to SCE and DIBL down to ultimate device dimensions of 30 to 50 nm.
International audienceAtomic layer deposition (ALD) of nickel and nickel carbide is reported starting from nickel acetylacetonate and a primary alcohol. The sequential reactions of both reactants with the adsorbed species are shown to be self-limited. Use of propanol or ethanol as reducing agents yields the formation of the technologically relevant carbon-Ni3C thin films, whereas the carbon content with use of methanol is less than 5 atom %. These metallic nickel thin films are electrically conductive and feature a soft ferromagnetic behavior. The thermally stable cubic lattice of nickel was grown at 300 degrees C with methanol as a reducing agent while the metastable hexagonal structure was obtained at lower temperatures. The morphology and the structure of the films were investigated with use of scanning electron microscopy and X-ray diffraction. The films are nanocrystalline featuring an average crystallite size of similar to 10 nm. Hydrogen-free ALD of nickel is particularly appealing for the deposition of (i) conformal coatings on hydrogen-sensitive substrates such as highly reducible oxides and metals with high capacity to form hydrides and (ii) 3D nanomaterials with high aspect ratio
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.