| AVS 54th International Symposium | |
| Plasma Science and Technology | Tuesday Sessions |
| Session PS1-TuA |
| Session: | Plasma Etching for Advanced Interconnects II |
| Presenter: | M.A. Goldman, University of California, Berkeley |
| Authors: | M.A. Goldman, University of California, Berkeley S.H. Kim, University of California, Berkeley D.B. Graves, University of California, Berkeley |
| Correspondent: | Click to Email |
It is widely understood that photoresist strip following dielectric etch often damages ultra low-k films. We measured the effects of molecular beams of ions and radicals impacting porous, ultra low-k dielectric films in a vacuum beam chamber to simulate damage induced by photoresist stripping under controlled conditions. Damage was characterized by ex-situ FTIR, contact angle measurements, SEM coupled with damaged layer etching, and AFM. We find that rare gas ions (Ar+ and Xe+) alone appear to damage only the near-surface region of the film. In addition, we report results on the mechanism of damage due to radical beams, including O, N, NHx, NO, and H. For oxygen radical damage on porous ultra low-k films, carbon abstraction and subsequent moisture uptake is shown to be a diffusion-limited process that occurs as a front of carbon depletion that penetrates through the film. Rare gas ion bombardment at normal incidence is shown to significantly reduce the damaging effects of O atoms, apparently by closing pores at the surface of the film.