Method for fabricating air gap with borderless contact

Abstract

A semiconductor structure having a first conductive trace fabricated adjacent to a second conductive trace over an insulating layer. A dielectric material is located over and between the first and second conductive traces. A borderless contact extends through the dielectric material to contact the first conductive trace. An air gap is formed in the dielectric material between the first and second conductive traces, thereby increasing the capacitance between the first and second traces. The air gap has a first portion with a first width adjacent to the borderless contact, and a second portion with a second width away from the borderless contact. The second width is greater than the first width, and the second portion of the air gap is substantially longer than the first portion of the air gap. The first portion of the air gap is offset toward the second trace. The second portion of the air gap maximizes the capacitance between the first and second traces, while the first portion of the air gap minimizes the contacted pitch of the first and second traces.