Combination of characterization techniques for atomic layer deposition MoO3 coatings: From the amorphous to the orthorhombic α-MoO3 crystalline phase

Abstract

Impact of titanium addition on film characteristics of Hf O 2 gate dielectrics deposited by atomic layer deposition J. Appl. Phys. 98, 054104 (2005); 10.1063/1.2030407Microstructure characterization of sol-gel prepared MoO 3 -TiO 2 thin films for oxygen gas sensors Thin films of MoO 3 deposited on Si(111) and Al 2 O 3 (001) substrates by atomic layer deposition have been investigated by x-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and Raman spectroscopy for detailed characterization of composition and morphology. Comparison of angle resolved x-ray photoelectron spectroscopy (ARXPS) and XPS depth profiles based on Ar þ sputtering is reported. Sputtering induces a reduction of molybdenum in MoO 3 from þIV to metallic Mo as the interface toward Si is approached, whereas ARXPS on a 10 nm thin film shows that Mo(VI) remains outside the interface toward Si where lower valent molybdenum compounds are formed. Upon annealing, the as-deposited amorphous thin films of MoO 3 crystallize into bor a-MoO 3 as identified by x-ray diffraction. The current study provides a convenient route toward formation of metastable b-MoO 3 and a full crystallization pathway from amorphous to crystalline a-MoO 3 . Combined AFM and Raman analysis have been performed on thin films of a-MoO 3 deposited on Al 2 O 3 (001) and prove that the crystallization proceeds via island growth at 600 C. The Raman intensity ratios between different bands depend strongly on morphology and size of crystalites.

Top‐Down Integration of Molybdenum Disulfide Transistors with Wafer‐Scale Uniformity and Layer Controllability

“…Initially, the sample was heated to 400 °C for 20 min under flowing Ar (7 sccm) gas to remove any organic contaminants on the surface and anneal the as-deposited amorphous MoO 3 into orthorhombic (α-MoO 3 ). [40] Then, for the sulfurization, the temperature was gradually increased from 400 to 500 °C over a period of 5 min and was maintained at 500 °C for 20 min with flowing Ar (7 sccm). The temperature at the sulfur powder reached about 150-200 °C to supply enough sulfur vapor pressure.…”

Film Growth Rates and Activation Energies for Core-Shell Nanoparticles Derived from a CVD Based Aerosol Process

“…Commercially available molybdenum hexacarbonyl and triphenyl bismuth were found to meet these requirements, are stable upon storage and handling and were therefore selected. CVD of MoO 3 and Bi 2 O 3 on planar substrates with these precursors has been reported [11,12,13,14,15,16]. However, little can be found with regard to the coating of micron sized or even submicron particles with such materials.…”

Far Field Combined AFM and Micro-Raman Imaging for Characterisation of Surface of Structured Catalysts: Example of Pd Doped CoOx Catalysts on Precalcined Kanthal Steel

“…The system can be harnessed for catalyst design and investigation in a number of ways including combined mapping, with (near field) [1] or without (far field) [2] tip enhanced Raman effect (TERS) as presented in Fig. 1.…”

“…The interaction of laser light with an AFM tip can improve Raman resolution by a vast array of near field effects [9] among which is enhancement of electric field that occurs on hot spots on surface of tips usually prepared from Au or Ag [1,2,[5][6][7]. There plasmon resonance at the surface of a tip (or sample) can occur, thereby increasing a cross section for Raman transitions, and in this way, generating a measured increase in signal intensity.…”