Influence of Process chamber ambient on SiOC (k=2.9) ILD Cu damascene ashing

The influence of dry etch and ash chamber ambient on inorganic low-k SiOC (k=2.9) Cu damascene interconnects is studied. In order to minimize erosion and damage to the SiOC film and the SiCN liner, fluorine atom density in the process chamber must be characterized. Knowledge of this study is applicable to so called "all-in-one" processes-integration of low-k etch, post ashing, and liner etch simultaneously in the same process chamber. This enables an improvement of productivity.