AVS 52nd International Symposium
    Plasma Science and Technology Tuesday Sessions
       Session PS-TuA

Paper PS-TuA6
Vacuum-Ultraviolet Photon Irradiation Effects in Fluorocarbon Plasmas on SiO@sub 2@ Etching Surface Reactions using In vacuo Electron-Spin-Resonance

Tuesday, November 1, 2005, 3:40 pm, Room 302

Session: Dielectric Etch II
Presenter: K. Ishikawa, Tohoku University, Japan
Authors: K. Ishikawa, Tohoku University, Japan
Y. Yamazaki, AIST, Japan
S. Yamasaki, AIST, Japan
S. Noda, Tohoku University, Japan
Y. Ishikawa, Tohoku University, Japan
S. Samuakwa, Tohoku University, Japan
Correspondent: Click to Email
Using in vacuo electron-spin-resonance (ESR) technique, where the real defect state can be detected without oxidation effect in air,@footnote 1@ surface reactions of fluorocarbon plasma etch of SiO@sub 2@ films were studied. To understand the reaction mechanism on the surface, creation of dangling bonds (DBs) on the surface are indeed a key process. In this study, we investigated the irradiation effects of vacuum ultraviolet (VUV) or ultraviolet (UV) photons on the surface reactions in the plasma etching processes through observation of the DBs creation. Soon after the plasma process, ESR spectra were measured following transferring to the ESR cavity under vacuum ambient. Experimental results showed that DBs are efficiently created by irradiation of plasma emissions such as VUV and UV photons. In fluorocarbon polymer, C-DBs with surrounding F atoms (Hyperfine interaction of 9.1 and 3.4mT.) are created by emissions of CF@sub 4@ plasmas (Intensive radiation in UV range at about 250nm by CF@sub x@). In amorphous fluorocarbon (a-C:F) films, the C-DBs may play roles of enhancement both of adsorption of gaseous CF@sub x@ radicals and of removal itself by bond-breaking in the polymer. On the other hand, Si-DBs (E' center) in the SiO@sub 2@ film are created by irradiation of emissions in VUV range below 140nm (Most of radiation in atomic emissions such as C, F, and Ar). We speculate tentatively that not only reactive species but also plasma characteristics as emissions affect to creation of the DBs, and the created DBs contributes on the surface reactions of the fluorocarbon plasma etching processes, especially employing high density plasmas. @FootnoteText@ @footnote 1@ K. Ishikawa, et al. Appl. Phys. Lett. 81, 1773 (2002).