Technique for intralevel capacitive isolation of interconnect paths

摘要

A technique is described for providing cavities between the conducting paths of an integrated semiconductor circuit. These cavities can have air or a gas trapped therein to decrease the dielectric constant between two conducting paths. After forming the conducting paths, an etchable fill material formed between and over the conducting paths. An oxide cap is formed over the fill material. Conducting plugs, extending through the fill material and the oxide cap, and electrically coupled to the conducting paths are formed. A photo-resist layer applied over the conducting plugs and the oxide cap. The photo-resist layer is structured to permit access to the oxide cap between the conducting plugs. A "pin-hole" is fabricated through the oxide cap and the fill material exposed by the "pin-hole" is etched away. The "pin-hole" is plugged with additional oxide cap material and a surface is then formed on the oxide cap exposing the conducting plugs. This structure is then ready for additional processing.