Recovery of fluoride toward sustainable integrated circuit manufacturing: quantifying water–energy–carbon–fluorine footprints in China

Integrated circuit (IC) industry in the world faces unprecedented environmental challenges like carbon neutrality, and China is serving as a critical manufacturing hub in this global supply chain. However, fluorinated chemicals used in IC manufacturing and discharged to wastewater systems remain underexamined in environmental assessments. This study integrates life cycle assessment, material flow analysis, PROMETHEE II, and support vector machine-based Sobol analysis to evaluate water, energy, carbon, and fluorine (WECF) footprints across IC manufacturing, fluorine-containing wastewater double membrane treatment, and sludge recycling in a representative Chinese IC plant. The results showed that chemical vapor deposition accounted for the highest energy consumption and contributed over 30% of greenhouse gas emissions, primarily due to the intensive energy required for managing fluorinated chemicals. Although most fluorine enters the wastewater system, sludge recycling serves as a highly effective pathway for recovery of approximately 32% of the total fluorine. Moreover, sludge recycling and double membrane treatment showed better WECF footprint performance than manufacturing processes. Furthermore, fluorinated chemicals and energy consumption emerged as the most interactive inputs, which demonstrates that the mitigation of fluorine would significantly increase the energy and carbon footprints. Scenario analysis showed that substituting fluorinated chemical inputs and optimizing steam use could cut fluorine and carbon footprint by up to 65% and 30%, respectively. These findings indicate that achieving sustainable IC manufacturing requires a transition from isolated energy efficiency measures to comprehensive management of WECF nexus, alongside the development of low-fluorine manufacturing alternatives.

Subjects

Fluorine-containing sludge

Integrated circuit

Life cycle assessment

Material flow analysis

Wastewater treatment

DDC Class

600: Technology

621.3: Electrical Engineering, Electronic Engineering

628.5: Environmental Chemistry

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Recovery of fluoride toward sustainable integrated circuit manufacturing: quantifying water–energy–carbon–fluorine footprints in China