AVS 51st International Symposium
    Plasma Science and Technology Monday Sessions
       Session PS1-MoM

Paper PS1-MoM2
Investigation of Fundamental Etching Reaction of Organic Low Dielectric Film Using Ion Beams with Radical Injection

Monday, November 15, 2004, 8:40 am, Room 213A

Session: Low-k Dielectric Etching
Presenter: M. Yuuhei, Nagoya University, Japan
Authors: M. Yuuhei, Nagoya University, Japan
H. Masaru, Nagoya University, Japan
G. Toshio, Nagoya University, Japan
A. Atsuhiro, Sony Co, Japan
T. Tetsuya, Sony Co, Japan
Correspondent: Click to Email
Etching of organic low dielectric (low-k) interlayer films has been an essential process in ULSIs. However, this process becomes more complex and requires the high accuracy. Therefore, quantitatively understanding of this process is very important. Low-k etching using plasma, it is impossible to control the radicals and ions independently and so it is difficult to clarify the etching mechanism quantitatively. In this study, the ion beam apparatus with radical injection was developed and applied to the investigation of fundamental reaction of organic low-k film. The apparatus is composed of Ar@super +@ beam source, electron shower gun, and radical injection source. A compact electron cyclotron resonance plasma source was used as a radical source. To remove the electrons and ions in the plasma, two retard electrodes were installed in front of the plasma source. Using the vacuum ultraviolet absorption spectroscopy, the absolute densities of H and N radical generated by radical source were evaluated. Etching sample was blanket film of SiLKTM. The etching subsurface reactions were measured by in-situ XPS. The etch rate by Ar@super +@ beam was enhanced by the injection of H and N radicals. Especially, the etching rates of injection of mixing radicals of H and N were high comparing with those of H or N radical. The C=N/C-N ratio of subsurface was increased with increasing N radical and H+N radical density under the Ar+ ion bombardment When H+N radical was injected under the high ion energies above 300eV, the C=N/C-N ratio was higher than those under the low ion energies. Consequently, the high C=N/C-N ratio of the subsurface is a key factor for the high etch rate of the organic low-k film.