摘要 |
Methods for manufacturing air-gap (e.g., side wall air-gap) containing metal/insulator interconnect structures for Very Large Scale Integrated (VLSI) and Ultra Large Scale Integrated (ULSI) devices and packaging comprise forming the air-gap spacers by deviating from a conventional dual-damascene etch process in order to avoid damage to the dielectric, and instead utilize intentional and controlled chemical damage of the Si, C, O, H containing dielectric by appropriate strip/ash etch chemistries after the trench etch and/or after via etch. The damaged dielectric layer is left in place after etch and the stack is taken through metallization and chemical mechanical planarization (CMP) processes. Subsequent to this, selective removal of the oxide-like damaged layer takes place by exposure to appropriate chemistries such as dilute HF, leaving behind air-gap spacers. Pinch-off cap deposition ensures integration of the air-gap for narrow air-gaps or perforated caps for wide air-gaps.
|