| abstract |
A method of forming a low dielectric constant film that can be used in a damascene process is disclosed. An organosilicon precursor such as octamethylcyclotrisiloxane (OMCTS) or any other compound that contains Si, C, and H and optionally O is transported into a PECVD chamber with a carrier gas such as CO or CO 2 to provide a soft oxidation environment that leads to a higher carbon content and low k value in the deposited film. The carrier gas may replace helium or argon that have a higher bombardment property that can damage the substrate. Since CO and CO 2 can contribute carbon to the deposited film, a lower k value is achieved than when an inert carrier gas is employed. The deposited film can be employed, for example, as a dielectric layer in a damascene stack or as an etch stop layer. |