AVS 50th International Symposium
    Plasma Science and Technology Thursday Sessions
       Session PS2-ThM

Paper PS2-ThM4
Low Damage Low-k Film Etching using Advanced Neutral Beams

Thursday, November 6, 2003, 9:20 am, Room 315

Session: Low k Dielectric Etch
Presenter: H. Ohtake, Tohoku University, Japan
Authors: H. Ohtake, Tohoku University, Japan
N. Inoue, Tohoku University, Japan
T. Ozaki, Tohoku University, Japan
S. Samukawa, Tohoku University, Japan
Correspondent: Click to Email
Low damage processes on the porous MSQ by using neutral beam were investigated. The porous MSQ is very vulnerable to the plasma exposure. Especially, the methyl is drawn out from the porous MSQ during the ashing process, which causes the increase of dielectric constant. In this paper, we investigated the application of the neutral beams to the ashing processes without the effect of ions and photons. In oxygen beam, we observed the increase of the dielectric constant of low-k film as much as that in the oxygen plasma. However, when we used the hydrogen beam, the MSQ dielectric constant did not change while it increased in the case of hydrogen plasma. According to the XPS analysis, it was found that the modified layer of carbon hydride is generated on the surface of porous MSQ by hydrogen beam exposure. This modified layer is thought to prevent the methyl from being drawn out from the porous MSQ. On the other hand, in the hydrogen plasma, it is thought that the generation of this modified layer is restricted by the photons or the ions. In addition, when we used the gas mixture beam of hydrogen and nitrogen, the modified layer of carbon nitride is generated on the surface of MSQ. This layer also prevents the methyl extraction from the porous MSQ. Accordingly, the low damage ashing-processes can be achieved by using hydrogen or hydrogen- nitrogen beam because of the generation of the modified layer.