Composite intermetal dielectric structure including low-k dielectric material

摘要

A method of forming a composite intermetal dielectric structure is provided. An initial intermetal dielectric structure is provided, which includes a first dielectric layer and two conducting lines. The two conducting lines are located in the first dielectric layer. A portion of the first dielectric layer is removed between the conducting lines to form a trench. The trench is filled with a second dielectric material. The second dielectric material is a low-k dielectric having a dielectric constant less than that of the first dielectric layer.