Thermal post-deposition treatment of halogen-doped films to improve film stability and reduce halogen migration to interconnect layers

摘要

A method of stabilizing a halogen-doped silicon oxide film to reduce halogen atoms migrating from said film during subsequent processing steps. A halogen-doped film is deposited over a substrate and then subjected to a degassing step in which the film is briefly heated to a temperature of between about 300 and 550 C. before deposition of a diffusion barrier layer. It is believed that such a heat treatment step removes loosely bonded halogen atoms from the halogen- doped film and thus the treatment is referred to as a degassing step. In a preferred version of this embodiment, the halogen-doped silicon oxide film is an FSG film that is subjected to a degassing treatment for between about 35 and 50 seconds.