Patent ID: 11152261

Abstract:
Techniques for self-aligned top via formation at line ends are provided. In one aspect, a method of forming self-aligned vias at line ends includes: patterning (even/odd) metal lines including using a (first/second) hardmask; cutting the hardmask and a select metal line, even or odd, using a cut mask having a window that exposes the hardmask over a cut region of the select metal line; enlarging the window to expose the hardmask on either side of the cut region; selectively etching the hardmask using the enlarged window to form a T-shaped cavity within the cut region; filling the T-shaped cavity with a gap fill dielectric; removing the hardmask; and recessing the metal lines, wherein the gap fill dielectric overhangs portions of the select metal line that, by the recessing, form the self-aligned vias at ends of the metal lines. A structure is also provided.