Imec Unveils Cutting-Edge Lithography Innovations to Slash CO2 Emissions in Semiconductor Manufacturing

Imec has introduced a climate-friendly method for creating patterns on chips through lithography and etching, aimed at advanced chip manufacturing.

Based in Leuven, Belgium, Imec highlights that this new technology can significantly reduce the carbon dioxide emissions associated with lithography and etch processes in semiconductor fabrication. The announcement occurred during the 2024 Advanced Lithography + Patterning Conference, where Imec showcased sustainable alternatives to minimize CO2 emissions in these critical manufacturing steps.

Photolithography is essential for producing integrated circuits, or semiconductor chips, as it utilizes light to transfer patterns onto substrates, typically silicon wafers, much like printing designs onto a chip surface. Imec's research indicates that lithography and etch processes account for over 40% of direct emissions in advanced logic node Scope 1 and Scope 2 categories. In 2021, semiconductor production generated approximately 175 megatonnes of CO2 equivalent, equivalent to the annual emissions of around 30 million people.

Imec's innovative alternatives aim to streamline dry etch processes while reducing the environmental impact without compromising semiconductor quality. A key component of their strategy is the Imec.netzero virtual fab model, developed through the Sustainable Semiconductor Technologies and Systems (SSTS) program. This model illustrates the emissions contribution from lithography and etch processes, underscoring the urgent need for sustainable advancements.

The research also proposes future directions for patterning, such as utilizing ultra-thin resists and underlayers, implementing minimal passivation, and adopting low process temperatures in etching. A notable achievement includes demonstrating a High-NA-compatible metal line etch process that reduces process gas emissions by approximately 94%.

Lithography remains a challenge, particularly regarding emissions from electricity generation. Engineers are exploring greener energy sources, reducing multi-patterning steps, minimizing photoresist doses, and improving scanner throughput for greater energy efficiency.

"Sustainability is crucial for Imec, and we’re encouraged to see it gaining focus at the SPIE Advanced Lithography and Patterning conference," said Emily Gallagher, a principal technical staff member at Imec. "An informal review of conference papers shows a promising trend: from just one paper on sustainability in 2018 to an anticipated 45 this year, with four from Imec. Given last year’s record-breaking climate events, it is vital for both organizations and individuals to act. Imec is committed to this initiative across all levels of our research."

Imec’s efforts in process innovation and sustainability illustrate a significant shift within the semiconductor industry towards eco-friendly manufacturing practices.