Practical Application of Directional Ion Beam Etching for Cost-Effective Sub-Lithographic Metal Line Fabrication

As Moore's Law continues to drive the semiconductor industry, the relentless scaling of device pitch presents significant manufacturing challenges. While multiple patterning techniques effectively break the lithographic limits to achieve the aggressive metal line pitches required for next-generation logic devices, their inherent complexity introduces substantial manufacturing costs. This escalating expense demands innovative, cost-effective solutions to maintain competitiveness. Traditional multiple patterning primarily addresses the lateral pitch between metal lines but falls short in reducing the critical line end-to-end pitch. Addressing this bottleneck currently necessitates multiple additional Extreme Ultraviolet (EUV) lithography masks, further compounding costs and process complexity. This work presents a transformative approach utilizing directional ion beam etching to precisely define sub-lithographic metal lines, circumventing the need for these expensive supplementary EUV steps. Through experimental validation, we demonstrate the feasibility and significant cost-reduction potential of this technology. We will discuss the advantages, current limitations, and essential future developments required for its full integration into advanced semiconductor manufacturing.