Energy-efficient optical crosslinking of underlayers for sustainable and low-power semiconductor manufacturing

Abstract

As the resource-intensive semiconductor industry progresses, concerns about environmental sustainability are intensifying, and efforts to achieve sustainable chip manufacturing are accelerating. As the complexity of process steps and nodes increases significantly to achieve narrower pitches, the lithography process, which consumes a substantial amount of power, has emerged as a critical issue in terms of electrical energy consumption. We propose a novel process that substantially reduces electricity consumption as a feasible alternative to the conventional thermal crosslinking approach. We provide a comprehensive discussion of an optical crosslinking system designed to crosslink underlayer materials, such as spin-on carbon and spin-on glass, solely through light exposure, thereby eliminating the need for heat. By replacing the traditional thermal baking system, which is energy-intensive, with the energy-efficient optical crosslinking system, we demonstrate the potential to save both energy and processing time on the track without compromising lithographic performance. To validate the feasibility of the proposed approach and materials, we conducted film crosslinking confirmation and etch rate tests using light-curable underlayer materials. Subsequently, we analyzed and evaluated the performance of pitch 28 nm line/space patterning under optimized curing conditions. The patterning tests with light-curable underlayers yielded competitive results compared with those with the thermal underlayer. The introduction of the innovative optical crosslinking system can contribute to harmonizing environmental sustainability with the semiconductor industry, providing ecological benefits and facilitating sustainable semiconductor manufacturing.