The Study of Property Changes of Methyl Silicon Oxide Films in the Ashing Process
Abstract
The development of low dielectric constant interlayer films for semiconductors and the integration process accommodating them are crucial subjects for reducing delay time. Methyl silicon oxide film, a low k film, shows different ashing characteristics for the O2 plasma ashing and O2 -reactive ion energy ashing process. Although the films do not dissolve in dilute HF solution before ashing, the former process yields films with high dissolubility and the latter yields films that slowly dissolve. A dissolution mechanism was investigated by density functional theory and molecular dynamics simulations. It was found that the methyl group is replaced by the OH group because of the O radicals, making the film porous and causing the high dissolution rate rate in dilute HF solution for the former process. For the latter process, after the methyl group is replaced by the OH group because of the O radicals and O ions, dehydration condensation occurs due to collision heating by O ions. This leads to the low dissolution rate.
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- March 2000
- Bibcode:
- 2000APS..MART21003K