AVS 49th International Symposium
    Thin Films Wednesday Sessions
       Session TF-WeP

Paper TF-WeP18
Raman Spectroscopy Measurement of TiO@sub2@ Sputtered Films Changing Degree of Plasma Exposure

Wednesday, November 6, 2002, 11:00 am, Room Exhibit Hall B2

Session: Poster Session
Presenter: N. Yamada, Toyama University, Japan
Authors: T. Takahashi, Toyama University, Japan
H. Nakabayashi, Toyama University, Japan
J. Tanabe, Toyama University, Japan
N. Yamada, Toyama University, Japan
W. Mizuno, Toyama Industrial Technology Center, Japan
Correspondent: Click to Email
The relationship between the Raman spectra and the crystallographic orientation of the TiO@sub2@ films deposited at different working gas pressures have been investigated in detail. The TiO@sub2@ films with thickness of about 800-2300 nm have been reactively deposited on glass-slide substrates at an atmosphere of Ar and O@sub2@ mixture, using the facing targets sputtering. The maximum deposition rate of the film was 12.8 nm/min. The Raman spectra, and the crystallographic orientation of the films were measured using Raman spectroscopy, and X-ray diffractometry, respectively. Most of films deposited in this study were transparent and had anatase crystal structure, while some of them were semitransparent. The anatase phase of as-deposited TiO@sub2@ films has revealed in the Raman spectra with a Raman shift of 145 cm@super-1@ and the X-ray diffraction patterns. When the TiO@sub2@ films have been deposited at the working gas pressures of 3 mTorr with increasing plasma exposure, the highest peak intensity with a Raman shift of 145 cm@super-1@ steeply increased, while the X-ray peak intensity of A(220) with preferential crystallographic orientation also steeply increased, where A shows the anatase phase of TiO@sub2@. On the other hand, in the films deposited at the working gas pressures of 1 mTorr with decreasing plasma exposure, the Raman peak intensity at 145 cm@super-1@ gradually decreased at the condition that the preferential crystal orientation changed from A(220) to A(101). This implies that the change in the Raman peak intensity at 145 cm@super-1@ may be closely related to the change in the A(220) peak intensity. The A(220) peak was significantly higher than other peaks when the TiO@sub2@ crystallites became larger regardless of the working gas pressure. Consequently, it was found that the Raman peak intensity at 145 cm@super-1@ in as-deposited TiO@sub2@ films were strongly affected by the plasma exposure related to the substrate position during film deposition.