Interlayer dielectric replacement techniques with protection for source/drain contacts

Abstract

Techniques are provided for fabricating a semiconductor integrated circuit device which implement an interlayer dielectric (ILD) layer replacement process to replace an initial sacrificial ILD layer with a low-k ILD layer, while forming silicide or dielectric capping layers to protect source/drain contacts of field-effect transistor devices from etch damage during the ILD replacement process. For example, source/drain contact openings (e.g., trenches) are formed in a sacrificial ILD layer and metallic source/drain contacts are formed in the source/drain contact openings. Protective capping layers (e.g., metal-semiconductor alloy capping layers or dielectric capping layers) are formed on upper surfaces of the metallic source/drain contacts. The sacrificial ILD layer is removed using an etch process to etch down the sacrificial ILD layer selective to the protective capping layers, and a low-k ILD layer is formed in place of the removed sacrificial ILD layer.