The Structural Changes of Indium-Tin Oxide and a-WO₃ Films by Introducing Water to the Deposition Processes

Abstract

Indium-tin oxide (ITO) films and amorphous WO3 (a-WO3) films were deposited by DC magnetron sputtering and EB evaporation, respectively, under different water partial pressures (p H2O). The ITO films sputtered under higher p H2O showed higher resistivities because of the decrease in hall mobility and had rather different orientation distributions of the crystal axis of the grains. It was found from XPS analyses that the In-O-H bonds which were not found in the films existed at the interface between the glass substrates and the ITO films, and much more of these bonds existed for the higher p H2O films. This suggests that the structural change which increased the resistivity occurred at the first stages of the formation of the films. For the a-WO3 films deposited under high p H2O, the decreases of order parameters and increases of W=O bonds were observed by Raman spectroscopy, indicating a decrease in microcrystal sizes.

Effect of oxygen partial pressure on the structural and optical properties of dc sputtered ITO thin films

“…Among these methods, we can cite the conventional e-beam evaporation [8], the reactive e-beam evaporation [9], the dc sputtering [10,11], the rf sputtering [12,13], the spray pyrolysis technique [14], sol-gel [15,16] and pulsed laser deposition [17]. These studies have shown that the physical properties of ITO films depend greatly on the method and conditions of deposition.…”

Electrical and optical properties of ZnO–WO3 nanocomposite and its application as a solid-state humidity sensor

“…The peaks at 803 and 715 cm −1 are Raman peaks of crystalline WO 3 (m-phase), which correspond to the stretching vibrations of the bridging oxygen [55]. These peaks are attributed to W-O stretching (ν), W-O bending (δ) and O-W-O deformation (γ ) modes [56,57]. Figure 11 shows absent of substantial peaks, which means no impurities were present in the samples.…”

Ultrasound-assisted oxidation of tungsten in oxygen plasma: the early stages of the oxide film growth

“…This conclusion is in good agreement with the data published previously about the influence of water partial pressure on the density of evaporated WO 3 films. 24 Figure 5(a) shows the AFM image taken of the sample oxidized without UST for a plasma exposure time of 3600 s. Normal oxidation does not change the surface morphology as compared to the pristine, i.e. unexposed, sample (not shown here) and is characterized by a similar value of the surface roughness (¾2.1 nm).…”