Selective local metal cap layer formation for improved electromigration behavior
A method of forming a wiring structure for an integrated circuit device includes forming one or more copper lines within an interlevel dielectric layer (ILD); masking selected regions of the one or more copper lines; selectively plating metal cap regions over exposed regions of the one or more copper lines; and forming a conformal insulator layer over the metal cap regions and uncapped regions of the one or more copper lines.
1. A method of forming a wiring structure for an integrated circuit device, the method comprising:
forming one or more copper lines within an interlevel dielectric layer (ILD);
masking selected regions of the one or more copper lines by forming a bottom antireflective coating (BARC) layer over the ILD layer and one or more copper lines, forming a photoresist layer over the BARC layer, patterning the photoresist layer, and removing portions of the BARC layer corresponding to patterning of the photoresist layer;
selectively plating metal cap regions over exposed regions of the one or more copper lines;
following the plating of the metal cap regions over the exposed regions of the one or more copper lines, removing remaining portions of BARC layer and photoresist layer; and
forming a conformal insulator layer directly on the metal cap regions and directly on uncapped regions of the one or more copper lines.