Room-temperature deposition of amorphous titanium dioxide thin film with high refractive index by a filtered cathodic vacuum arc technique

Abstract

Amorphous titanium dioxide (TiO2) thin film has been prepared by a filtered cathodic vacuum arc technique at room temperature. It was concluded from the core level of Ti 2p 3/2 (458.3 eV) and O 1s (529.9 eV) and their deviation in binding energy (deltaBE = 71.6 eV) that only one of Ti oxidation states, Ti4+, existed in the film and the film was of ideal stoichiometry. The film possessed high transmittance, which can reach as high as that of a quartz substrate, especially in the visible range, owing to its optical bandgap of 3.2 eV. The high refractive index (2.56 at 550 nm) and low extinction coefficient (approximately 10(-4) at 550 nm) suggested that the film had a high packing density and a low scattering-center concentration. These good optical properties implied the film prepared by this technique was a promising candidate for optical application. Besides, the film was found to transform in the structure from amorphous to anatase crystalline when it was annealed at 300 degrees C, as evidenced by Raman and x-ray diffraction.

Study of nanocrystal TiO2 thin films by thermal annealing

“…2. The frequency and assignment of the Raman bands of anatase and rutile titania could be found in the literature [9]. No Raman peaks could be observed for the as-grown film and the film annealed at 250 • C. Above 250 • C, several separate peaks with differently relative intensity were observed as shown in curves (b)-(d).…”

“…Titanium dioxide thin films were deposited by as described in detail elsewhere [9]. The films were grown on Si (100) substrates at room temperature with the growth pressure of 3 × 10 −4 Torr.…”

“…Furnace annealing, as a convenient and low-cost method, has also been widely used to obtain crystalline materials [6][7][8]. However, using this method seldom work was reported on the properties of nanocrystalline TiO 2 thin films by filtered cathode vacuum arc (FCVA), which is a promising technique to deposit dense thin films with high quality [9,10]. Thus, in this work, post-annealing of TiO 2 thin films by FCVA was carried out.…”

Structure and optical properties of solution deposited TiO2 films

“…where n r ¼ 2.65 [26], n a ¼ 2.56 [27] and the fractions of rutile, f r , and amorphous, f a , phases are 0.29 and 0.71, respectively. For voids filled with air, n v ¼ 1, the void fraction, f v , calculated using Eq.…”

Property study of aluminium oxide thin films by thermal annealing

“…There are many methods has been used to deposit aluminium oxide thin films. Compared with other techniques, such as magnetic sputtering [5,6], plasma-enhanced chemical vapour deposition [7,8], metal organic chemical vapour deposition [9,10] and dual ion beam sputtering [11,12], filtered cathodic vacuum arc (FCVA) has been used to form metal oxide and nitride thin films [13][14][15][16][17][18][19][20] not only due to the characteristics of high ionization ratio and high ion energy (50 eV ~ 150 eV) but also the effective removing of the macroparticals and therefore resulting in high quality films [21,22].…”