Modification of Sol-Gel Thin Films By Ion Implantation
- PDF / 320,834 Bytes
- 6 Pages / 414.72 x 648 pts Page_size
- 51 Downloads / 220 Views
to IxlO1 5 ion/cm2 at acceleration energies 100 to 150 keV (Nisshin Electric Co., NH-20SR). The refractive index, n, and the thickness, d, of the films were measured using an automatic ellipsometer (Shimadzu, AEP-100). FTIR absorption spectra were measured for the ion implanted films coated on Si (Bio-Rad Labs., FTS-65). The dynamic microhardness, DMH, measurements were made for the coatings and the glass plates before and after ion implantation by the nano-indentation method (Shimadzu, DUH-200). The loading rate was 0.144 gf/s, and the maximum load was 50 gf. X-ray diffraction, XRD, measurements were made for the films using CuKa radiation and a rotating sample holder for thin films (Rigaku, 2651AI). Chemical analysis of the implanted films was made by SIMS (Ulvac Phi, SIMS-6500). RESULTS AND DISCUSSION Crystallization of TiO2 films Fig. I shows the XRD patterns for TiO2 films. The films were amorphous after heat treating at 300%C or lower temperatures. Diffraction peaks of Anatase were found for the films heated at 400%C or higher temperatures. The diffraction peaks of other phases were not observed. The phase transition from Anatase to Rutile was not observed for the films heat treated at temperatures up to 900°C, although the phase transition was observed for TiO2 powder prepared by the sol-gel method [121. The diffraction peaks of crystalline TiO2 were not found for the films heat treated at temperatures lower than 300%C and implanted with Ar+ or B+ (Fig. 2, b and c). Crystallization of the amorphous TiO2 films was not enhanced by ion implantation. X-ray diffraction patterns of the crystalline TiO2 films, heat treated at 400%C or higher temperatures, scarcely changed after Ar+ and B+ implantation (Fig. 2, e and f). However, the peak intensity of the films implanted with Ar+ was relatively weak (Fig. 2, e). Ion implantation with relatively low energy ions, 100 to 150 keV Ar+ or B+, did not remarkably affect the crystallization behavior of the sol-gel TiO2 films.
f 20
40 24 (degree)
20
Go
Fig. 1 XRD patterns for TiO2 films after heat treating at (a) 300, (b) 400, (c) 500, (d) 700, and (e) 900°C for 30 min. (CuKot)
40 24 (degree)
60
Fig. 2 XRD patterns for TiO2 films, (a) dried at 50'C, (b) dried and Ar+ implanted, (c) dried and B+ implanted, (d) heated at 500°C, (e) heated and Ar+ implanted, and (f) heated and B+ implanted. (Acc. energy; 100 keV, Dose; ixl0 1 4 ion/cm2 ) (CuKa)
184
Densification of TiO? films The thickness of TiO2 films decreased and the refractive index increased with increasing heat treating temperatures as shown in Fig. 3, H. The significant increase in refractive indices in the temperature range from 100%C to 400%C seems to be attributed to the densification of the films by solvent evaporation and crystallization. The refractive indices and d of the films after ion implantation are also shown in Fig. 3. The n and d of the films hardly changed with B+ implantation. On the other hand, after Ar+ implantation, the n and d of the films dried at 50 and 100%C became nearly the same as t
Data Loading...
