Patent ID: 6838355

Claim:
A method of forming an interconnect structure on a substrate, the method comprising the steps of: depositing at least one dielectric layer on the substrate, the dielectric layer being formed of at least one first dielectric material; embedding at least one conductive interconnect in the dielectric layer, the conductive interconnect having sidewalls in contact with the first dielectric material, wherein the conductive interconnect has a top surface coplanar with the top surface of the dielectric layer; removing a portion of the first dielectric material in selected areas of the dielectric layer, thereby forming at least one opening in the dielectric layer, such that the sidewalls of the conductive interconnect remain in contact with the first dielectric material, wherein the portion of the first dielectric material is removed by a method comprising the steps of: forming a cap on each conductive interconnect, the cap having a lateral extent greater than that of the conductive interconnect, thereby masking portions of the dielectric layer adjacent to the conductive interconnect and leaving other portions of the dielectric layer not masked; and removing a portion of the first dielectric material in areas of the dielectric layer not masked by the cap, thereby forming the at least one opening in the dielectric layer; and filling the opening with a second dielectric material.