Some embodiments relate to a semiconductor structure including a first inter-level dielectric (ILD) layer overlying a substrate. A lower conductive via is disposed within the first ILD layer. A plurality of conductive wires overlie the first ILD layer. A second ILD layer is disposed laterally between the conductive wires, where the second ILD layer comprises a first material. A sidewall spacer structure is disposed between the second ILD layer and the plurality of conductive wires. The sidewall spacer structure continuously extends along opposing sidewalls of each conductive wire. A top surface of the sidewall spacer structure is vertically above a top surface of the plurality of conductive wires, and the sidewall spacer structure comprises a second material different from the first material.