Method for forming interconnect structure with low dielectric constant

摘要

The present invention provides a method for forming low dielectric constant inter-metal dielectric layer. The method comprises providing a semiconductor structure and forming a first dielectric layer on the semiconductor structure. Conductor structures are formed in the first dielectric layer. The partial first dielectric layer is removed by using the conductor structures as etching mask. A second dielectric layer is formed between the conductor structures, which has a dielectric constant smaller than the first dielectric layer. The second dielectric layer also alternatively has air voids contained therein to reduce dielectric constants.