ICP ETCHING AND STRUCTURE STUDY OF PECVD SiC FILMS

Abstract

Results of Induction Coupled Plasma (ICP) etching of as-prepared and annealed PECVD hydrogenated amorphous silicon carbide (a-Siix C x :H) films using CF4/O2 chemistry are presented. The etch rate of the annealed films decreased with an increase in annealing temperature. Infrared spectra for the annealed films showed a significant decrease in the Si-H and C-H bonds, and a pronounced increase in the Si-C bonds. The XRD results showed several poly-crystalline Si-C structure in films annealed at 800°C. ESR spectra show the density of the dangling bonds increased as a function of annealing temperature. The drop in etch rate of the annealed films is due to the reduction in porous structures resulted from dehydrogenation and increased crystallinity of the film.(2) J COHere, a(co) is the absorption coefficient, co the wavenumber, A the inverse cross section coefficients for the Si-H (1.35xl0 21 ), C-H (1.35xl0 21 ) and Si-C (2.13xl0 19 ) bonds [4]. The XRD measurements were carried with a CuKoc radiation. A Plasma-Therm SLR770 4318 Int. J. Mod. Phys. B 2002.16:4318-4322. Downloaded from www.worldscientific.com by UNIVERSITY OF WATERLOO on 02/03/15. For personal use only.

Tuning Hydrophobicity of TiO2 Layers with Silanization and Self-Assembled Nanopatterning

“…While sol–gel TiO 2 is amorphous, sputtered and thermal TiO 2 have crystalline structures. It appears that the etching rate of amorphous structures seems to be greater than that of crystalline structures, which is consistent with the earlier findings by Shi et al . Regarding the greater resistance of thermal TiO 2 to etching than sputtered TiO 2 , we ascribe this property to the annealing temperature or the phase of the TiO 2 .…”

“…On the basis of these XRD spectra, we found that the sputtered TiO 2 exists in the anatase phase (annealed at 400 °C in 4 h), whereas the phase of the thermal TiO 2 is rutile (annealed at 500 °C in 8 h). Shi et al claimed that the improvement of crystallinity after annealing results in a stronger bonded network, lowering the etch rate . In the experiment, the sol–gel TiO 2 samples are best for tuning hydrophobic behaviors of TiO 2 layers because ICP etching has a greater impact on the morphology change of the sol–gel TiO 2 .…”

“…Shi et al claimed that the improvement of crystallinity after annealing results in a stronger bonded network, lowering the etch rate. 37 In the experiment, the sol−gel TiO 2 samples are best for tuning hydrophobic behaviors of TiO 2 layers because ICP etching has a greater impact on the morphology change of the sol−gel TiO 2 . We have measured AFM topography images of nonetched, 20s-etched, and 30s-etched sputtered TiO 2 as representative samples.…”