Structural effect on intrinsic stress in nanocrystalline Si:H films

• Published in: Vacuum 2011-09, Vol.86 (2), p.151-155
• Main Authors: Wei, Wensheng, Su, Jianling, Zhang, Congliang, Chu, Liang, Wang, Tianmin
• Format: Article
• Language: English
• Subjects: Chemical vapor deposition; Compressive properties; Confinement; Fano effect; Intrinsic compressive stress; Nanocrystalline Si:H; Nanocrystals; Phonon confinement; Phonons; Plasma enhanced chemical vapor deposition; Raman scattering; Stresses
• ISSN: 0042-207X; 1879-2715
• DOI: 10.1016/j.vacuum.2011.05.004

Intrinsic stress in nanocrystalline Si:H films which prepared by the plasma enhanced chemical vapor deposition (PECVD) technique, was illustrated as a compressive stress by means of Raman scattering and radius of curvature measurement. The Raman signals can be well fitted by a model of strain-calibrated phonon confinement, where the sole effect of phonon confinement and Fano interference on Raman scattering was excluded, respectively. The ion bombardment effect on the origination of intrinsic stress in the PECVD films was discussed. The formation of nc-Si:H was explained by etching model in present experimental parameters’ range. The results infer that the intrinsic compressive stress shows intensive correlation to amorphous Si:H, grain boundaries and hydrogen incorporation in the as-deposited materials. [Display omitted] ► Nanocrystalline Si:H films were prepared by PECVD technique. ► Intrinsic compressive film stress was revealed by Raman and curvature radius skill. ► Raman signals were well fitted by a model of strain-calibrated phonon confinement. ► The compressive stress shows intensive correlation to material structures. ► It is noted one should evaluate carefully nanomaterial's stress with Raman method.