Radiofrequency power effects on the optical and structural properties of hydrogenated silicon films prepared by radiofrequency magnetron sputtering

• Published in: Thin solid films 2013-10, Vol.545, p.245-250
• Main Authors: Bouizem, Y., Abbes, C., Kefif, K., Sib, J.D., Benlakehal, D., Kebab, A., Chahed, L.
• Format: Article
• Language: English
• Subjects: Amorphous material; Composition and phase identification; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Constants; Cross-disciplinary physics: materials science; rheology; Deposition by sputtering; Exact sciences and technology; Infrared radiation; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Magnetron sputtering; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Nanostructures; Non-crystalline materials; Optical instruments, equipment and techniques; Optical properties; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of specific thin films; Physics; Polarimeters and ellipsometers; Radiofrequency; Silicon films; Spectroscopy; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology; Thin films; Vibration mode
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2013.08.053

The optical and structural properties of hydrogenated silicon films, deposited by radiofrequency (rf) magnetron sputtering at low temperature (Ts=100°C), were carefully investigated by means of optical transmission measurements (OT), Fourier transform infrared (IR) spectroscopy and spectroscopic ellipsometry (SE) technique. By varying the rf-power from 100W to 350W, and keeping all other parameters of the plasma constant, the growth rate increases up to 1.02nm/s. A remarkable change in the hydrogen-bonding configurations for both wagging and stretching vibration modes was observed. The observed changes demonstrate definite structural transformation of the films from a completely amorphous phase to another one with crystalline Si when the rf-power is increased from 180W to 200W. The difference between the two phases is well revealed by the OT and the IR absorption results, and strongly confirmed by the SE ones. The effect of hydrogen on the band gap and on the microstructure of the films is discussed. •By varying the rf-power from 100W to 350W, the growth rate increases up to 10.2Å/s.•A remarkable change in the hydrogen-bonding configurations was observed.•For films deposited at rf-power below 180W, the structure is completely amorphous.•The crystallization occurs around 200W.•The size grains of Si crystallites in the films depend on the rf-power.