Measurement-Based Estimation of Emission Factors for CF4, C4F6, and C4F8 in Semiconductor Etching Under Varying Plasma Conditions
Source abstract
Abstract
In the semiconductor industry, fluorinated gases with high global warming potential (GWP) are recognized as significant sources of greenhouse gas emissions. This study presents a measurement-based analysis of a 300 mm wafer etching process using CF4, C4F6, and C4F8 gases. The use rate of gas (Ui), unreacted fraction (1-Ui), and by-product generation rate (Bi) were evaluated under varying plasma intensity conditions. The results show that the unreacted fraction (1-Ui) decreased with increasing plasma intensity for all process gases, indicating enhanced gas dissociation efficiency. In contrast, the by-product generation rate (Bi) exhibited non-linear behavior due to the complex interplay of dissociation and recombination reactions within the plasma. Furthermore, the measured Ui and Bi values showed significant deviations from the default emission factors provided in the 2006 IPCC Guidelines and the 2019 Refinement. Variability analysis based on the coefficient of variation (CV) was conducted using measurements obtained under different plasma conditions (n = 3). The results indicate that Ui exhibited relatively stable behavior with low variability (CV < 0.3), whereas Bi showed higher variability depending on the type of by-product gas, reflecting stronger sensitivity to process conditions. These findings highlight that IPCC default emission factors may not adequately reflect actual process conditions and underscore the importance of incorporating measurement-based, condition-dependent variability into emission estimation.
Source: crossref · Quality: baseline
Research context
OpenAlex topics: Plasma Diagnostics and Applications · Plasma Applications and Diagnostics · Gas Dynamics and Kinetic Theory
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
Affiliations
Climate Change & Environment Research Center, Sejong University, Seoul 05006, Republic of Korea
Department of Statistics, Duksung Women’s University, Seoul 01369, Republic of Korea
Korea Testing & Research Institute (KTR), Gwacheon-si 13810, Republic of Korea
Department of Climate and Environment, Sejong University, Seoul 05006, Republic of Korea
Funding
Korea Environment Industry & Technology Institute · Ministry of Climate, Energy and Environment
References (32)
Show source-provided references
1. Yin, Y., and Yang, Y. (2025). Sustainable Transition of the Global Semiconductor Industry: Challenges, Strategies, and Future Directions. Sustainability, 17.10.3390/su17073160 ↗
2. Optimizing Greenhouse Gas Emission Quantification and Assessing Mitigation Effectiveness in Semiconductor Manufacturing10.1021/acs.est.5c18597 ↗
3. (2026, February 10). US EPA, Available online: https://www.epa.gov/eps-partnership/semiconductor-industry.
4. KIET (Korea Institute for Industrial Economics & Trade) (2020). Current Status and Mid- to Long-Term Challenges of Greenhouse Gas Emissions in the Semiconductor and Display Industries, Korea Institute for Industrial Economics & Trade.
5. Pelcat, M. (2023). GHG Emissions of Semiconductor Manufacturing in 2021. [Doctoral Dissertation, INSA Rennes].
6. KITECH (Korea Institute of Industrial Technology) (2024). Strategies for Reducing Greenhouse Gas Emissions from Semiconductor Processes, Korea Institute of Industrial Technology.
7. Pinto, A.M.F.R., Oliveira, V.B., and Falcão, D.S. (2018). 7-Miniaturization of direct alcohol fuel cells: Microfabrication techniques and microfluidic architectures. Direct Alcohol Fuel Cells for Portable Applications, Academic Press.10.1016/B978-0-12-811849-8.00007-3 ↗
8. Review of essential use of fluorochemicals in lithographic patterning and semiconductor processing
9. Future of plasma etching for microelectronics: Challenges and opportunities10.1116/6.0003579 ↗
10. IPCC (2023). Climate Change 2023 Synthesis Report, IPCC.
11. GHG Protocol (2024). IPCC Global Warming Potential Values, GHG Protocol.
12. Modeling China’s semiconductor industry fluorinated compound emissions and drafting a roadmap for climate protection10.1016/j.ijggc.2008.02.010 ↗
13. Repurposing of F-gases: Challenges and opportunities in fluorine chemistry10.1039/D1CS01072G ↗
14. UNFCCC (United Nations Framework Convention on Climate Change) (2026, February 01). Enhanced Transparency Framework-Technical Material. Available online: https://unfccc.int/process-and-meetings/transparency-and-reporting/support-for-developing-countries/consultative-group-of-experts/enhanced-transparency-framework-technical-material.
15. GIR (Greenhouse Gas Inventory and Research Center) (2025). National Greenhouse Gas Inventory Document of Republic of Korea 2024.
16. German Environment Agency (2025). National Inventory Reportfor the German Greenhouse Gas Inventory 1990–2023.
17. ISPRA (Italian Institute for Environmental Protection and Research) (2025). Italian Greenhouse Gas Inventory 1990–2023. National Inventory Document 2025, Italian Institute for Environmental Protection and Research.
18. Ministry of the Environment of Japan (2025). National Greenhouse Gas Inventory Document of JAPAN.
19. DESNZ (Department for Energy Security and Net Zero of the United Kingdom) (2025). UK Greenhouse Gas Inventory 1990 to 2023: Annual Report for Submission Under the Framework Convention on Climate Change.
20. Advances in core technologies for semiconductor manufacturing: Applications and challenges of atomic layer etching, neutral beam etching and atomic layer deposition10.1039/D4NA00784K ↗
21. Huff, M. (2021). Recent Advances in Reactive Ion Etching and Applications of High-Aspect-Ratio Microfabrication. Micromachines, 12.10.3390/mi12080991 ↗
22. Romano, L. (2025). Etching: The Art of Semiconductor Micromachining. Micromachines, 16.10.3390/mi16020213 ↗
23. Sammut, S. (2025). A Comprehensive Review of Plasma Cleaning Processes Used in Semiconductor Packaging. Appl. Sci., 15.10.3390/app15137361 ↗
24. Radical-controlled plasma processes10.1007/s41614-022-00084-2 ↗
25. Jin, H., Zheng, N., Deng, W., and Chen, X. (2017). Research on the chemical reaction in CF4 plasma during fused silica processing. 2017 6th International Conference on Measurement, Instrumentation and Automation (ICMIA 2017), Atlantis Press.10.2991/icmia-17.2017.27 ↗
26. Takagi, S., Hsiao, S.-N., Imai, Y., Sekine, M., and Matsunaga, F. (2025). Role of CF4 Addition in Gas-Phase Variations in HF Plasma for Cryogenic Etching: Insights from Plasma Simulation and Experimental Correlation. Plasma, 8.10.3390/plasma8040048 ↗
27. A kinetic study of the plasma-etching process. I. A model for the etching of Si and SiO2 in CnFm/H2 and CnFm/O2 plasmas10.1063/1.331074 ↗
28. Reaction probability for the spontaneous etching of silicon by CF3 free radicals10.1116/1.584421 ↗
29. IPCC (Intergovernmental Panel on Climate Change) (2006). 2006 IPCC Guidelines for National Greenhouse Gas Inventories, Intergovernmental Panel on Climate Change.
30. IPCC (Intergovernmental Panel on Climate Change) (2019). 2019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories, Intergovernmental Panel on Climate Change.
31. (2018). Measurement Methods for the Volumetric Flow of Non-CO2 Greenhouse Gases (CF4, NF3, SF6, N2O) Used in Semiconductor and Display Processes (2018) (Standard No. KS I 0587).
32. NIER (National Institute of Environmental Research) (2024). N2O, HFCs, PFCs, SF6, NF3 of Greenhouse Gas in Industrial Process—Fourier Transform Infra-Red Spectroscopy (ES 13501).