Patent ID: 6251798
Filing Date: 2001-06-26
Classification: H01L

Abstract:
A method for forming air gaps between conducting lines of a semiconductor device, comprising the steps of:providing a semiconductor substrate on the surface of which a base layer has been created;depositing a metal layer on said base layer;etching said metal layer into a pattern to form metal leads, said metal leads having tops and sidewalls with a spacing or gap between said metal leads, wherein said base layer is exposed in areas of said gaps between said metal leads;depositing a plasma resist layer on said metal leads and on said exposed portions of said base layer;positioning a reticle;positioning a source of radiation above said reticle in such a manner that said reticle selectively blocks radiation from areas of spacing or gaps between said metal leads;exposing the surface of said plasma resist layer to radiation, said radiation partially passing through and partially being intercepted by said reticle, creating unexposed plasma resist that aligns with said gaps between said metal leads;controlling depth of said exposure such that said exposure does not penetrate below said surface of said metal lines;removing unexposed plasma resist material, creating openings in said layer of plasma resist that align with said gaps between said metal leads; andclosing openings created by removal of said unexposed plasma resist material.