@article{oai:nagoya.repo.nii.ac.jp:00005469,
 author = {Fujita, Kazushi and Hori, Masaru and Goto, Toshio and Ito, Masafumi},
 issue = {1},
 journal = {Journal of Vacuum Science & Technology A},
 month = {Jan},
 note = {Environmentally benign etching process of amorphous silicon (a-Si) and tungsten (W) by using a plasma process with an evaporation of solid materials system has been developed for replacing a conventional plasma process using green house gases, such as SF_6 gas and perfluorocompound gases causing global warming. The evaporation system was designed to generate fluorocarbon species from solid materials by a CO_2 laser irradiation. An electron cyclotron resonance (ECR) plasma using O_2 accompanied with injection of species evaporated from solid materials has been applied to a-Si and W etching for cleaning process in chemical vapor deposition chamber. Fluorinated ethylene propylene (FEP) and polytetrafluoroethylene (PTFE) are selected as the solid material and the etching characteristics between FEP and PTFE have been compared. Furthermore, the etching of a-Si and W films has been performed in the divergent magnetic field ECR downstream plasma [electron density (n_e); ～10^10 cm^-3, electron temperature (T_e); 1.5–2.8 eV] and a planar ECR plasma [n_e ; ～10^10 cm^-3, T_e ; 3.4–4.4 eV] using O_2 gas with FEP evaporation. As a result, high etching rates of a-Si and W films of above 100 nm/min were successfully obtained at a substrate temperature of 400 ℃ in the planar ECR plasma of higher electron temperature. CF_x (x=1–3) radical densities and F atom density in plasmas were measured by an infrared diode laser absorption spectroscopy and an actinometric optical emission spectroscopy, respectively. On the basis of these measurements of species, the etching mechanisms of a-Si and W films are discussed.},
 pages = {302--309},
 title = {Environmentally benign etching process of amorphous silicon and tungsten using species evaporated from polytetrafluoroethylene and fluorinated ethylene propylene},
 volume = {21},
 year = {2003}
}