US Patent 11335638 Reducing RC delay in semiconductor devices

The present disclosure describes a method for reducing RC delay in radio frequency operated devices or devices that would benefit from an RC delay reduction. The method includes forming, on a substrate, a transistor structure having source/drain regions and a gate structure; depositing a first dielectric layer on the substrate to embed the transistor structure; forming, within the first dielectric layer, source/drain contacts on the source/drain regions of the transistor structure; depositing a second dielectric layer on the first dielectric layer; forming metal lines in the second dielectric layer; forming an opening in the second dielectric layer between the metal lines to expose the first dielectric layer; etching, through the opening, the second dielectric layer between the metal lines and the first dielectric layer between the source/drain contacts; and depositing a third dielectric layer to form an air-gap in the first and second dielectric layers and over the transistor structure.