Mechanical Engineering Research Team Led by Professor Kim Sang-yup Publishes Paper in the Prestigious International Journal “Polymer Testing”
Sogang University Mechanical Engineering Professor Kim Sang-yup’s research team has elucidated the critical role of “thermal history” in determining the performance of spin-on carbon (SOC) hard masks—a key material for next-generation semiconductor ultra-fine processes. The findings were published in the internationally renowned journal Polymer Testing, a leading publication in materials and polymers. Conducted as an industry-academia collaborative research project with Samsung Electronics, the study featured Mr. Song Jin-woo, an M.S.–Ph.D. student in Sogang University’s Department of Mechanical Engineering, as the first author, and Professor Kim Sang-yup as the corresponding author.
SOC hard masks are essential materials that facilitate the precise transfer of patterns to underlying layers during ultra-fine semiconductor fabrication. Their application has been expanding rapidly due to their exceptional planarization capabilities, which effectively fill surface irregularities. However, they typically exhibit lower etch resistance compared to conventional amorphous carbon films produced via chemical vapor deposition (CVD). Consequently, previous researches have been largely confined to designing the molecular structures of precursors or simply adjusting the final baking temperatures.
The research team focused on the fact that final material performance is determined not merely by the peak target temperature, but by the cumulative “thermal history” the material experiences on its path to that temperature. To analyze this, they established a three-component distributed activation energy model (DAEM) to design heat treatment pathways that theoretically yield the same degree of carbonization under varying temperature trajectories. The experiments revealed that a high-temperature, short-duration treatment (700 °C for 1 minute)—which minimizes the thin film’s exposure to residual oxygen in the vacuum chamber—boosted etch resistance by 26.4% and slashed surface defect density by 6.5% compared to a low-temperature, long-duration treatment (650 °C for 112 minutes) that achieved an identical degree of carbonization. Through spectroscopic analysis, the team proved that between the two competing reactions—bulk carbonization and surface oxidation—damage from surface oxidation becomes increasingly dominant as the heat treatment window lengthens.
This study holds significant weight as it shifts the material optimization paradigm for next-generation semiconductor processes beyond a simple equilibrium-focused approach toward a new design standard rooted in a kinetic perspective. Crucially, by delivering practical guidelines to secure the required etch resistance even within the residual oxygen environments unavoidable in industrial production, it opens new avenues to simultaneously enhance process productivity and manufacturing quality.
The first author, Mr. Song Jin-woo, stated, “While conventional hard mask research has heavily leaned toward foundational material development, it is deeply meaningful that we demonstrated the kinetic importance of the heat treatment pathway alongside performance enhancement via carbonization.” He added, “I hope managing the competitive dynamics between surface oxidation and bulk carbonization offers a practical blueprint for ensuring both productivity and quality in ultra-fine semiconductor patterning.” He expressed further gratitude, adding, “I would like to extend my deepest thanks to Professor Kim Sang-yup for his unreserved guidance throughout this project, and to our co-researchers at Samsung Electronics for tackling these real-world industrial bottlenecks alongside us.”
Meanwhile, this study was backed by funding from Samsung Electronics and the National Research Foundation of Korea.
▶Paper Title: Effect of thermal history on the competitive carbonization and surface oxidation of Spin-on Carbon hardmasks
[SEO keyword]
SOC hard masks, semiconductor ultra-fine processes, heat treatment pathways
SOC hard masks are essential materials that facilitate the precise transfer of patterns to underlying layers during ultra-fine semiconductor fabrication. Their application has been expanding rapidly due to their exceptional planarization capabilities, which effectively fill surface irregularities. However, they typically exhibit lower etch resistance compared to conventional amorphous carbon films produced via chemical vapor deposition (CVD). Consequently, previous researches have been largely confined to designing the molecular structures of precursors or simply adjusting the final baking temperatures.
The research team focused on the fact that final material performance is determined not merely by the peak target temperature, but by the cumulative “thermal history” the material experiences on its path to that temperature. To analyze this, they established a three-component distributed activation energy model (DAEM) to design heat treatment pathways that theoretically yield the same degree of carbonization under varying temperature trajectories. The experiments revealed that a high-temperature, short-duration treatment (700 °C for 1 minute)—which minimizes the thin film’s exposure to residual oxygen in the vacuum chamber—boosted etch resistance by 26.4% and slashed surface defect density by 6.5% compared to a low-temperature, long-duration treatment (650 °C for 112 minutes) that achieved an identical degree of carbonization. Through spectroscopic analysis, the team proved that between the two competing reactions—bulk carbonization and surface oxidation—damage from surface oxidation becomes increasingly dominant as the heat treatment window lengthens.
This study holds significant weight as it shifts the material optimization paradigm for next-generation semiconductor processes beyond a simple equilibrium-focused approach toward a new design standard rooted in a kinetic perspective. Crucially, by delivering practical guidelines to secure the required etch resistance even within the residual oxygen environments unavoidable in industrial production, it opens new avenues to simultaneously enhance process productivity and manufacturing quality.
The first author, Mr. Song Jin-woo, stated, “While conventional hard mask research has heavily leaned toward foundational material development, it is deeply meaningful that we demonstrated the kinetic importance of the heat treatment pathway alongside performance enhancement via carbonization.” He added, “I hope managing the competitive dynamics between surface oxidation and bulk carbonization offers a practical blueprint for ensuring both productivity and quality in ultra-fine semiconductor patterning.” He expressed further gratitude, adding, “I would like to extend my deepest thanks to Professor Kim Sang-yup for his unreserved guidance throughout this project, and to our co-researchers at Samsung Electronics for tackling these real-world industrial bottlenecks alongside us.”
Meanwhile, this study was backed by funding from Samsung Electronics and the National Research Foundation of Korea.
▶Paper Title: Effect of thermal history on the competitive carbonization and surface oxidation of Spin-on Carbon hardmasks
[SEO keyword]
SOC hard masks, semiconductor ultra-fine processes, heat treatment pathways