Life cycle assessment of semiconductor cleanroom buildings and fab infrastructure

Context

Environmental assessments of semiconductor manufacturing often focus on the electricity, gases, chemicals, and water used during production. The buildings and facility systems that support this production receive much less attention and are often represented using generic construction factors or excluded from the model altogether. A recent scope revision of imec.netzero, imec’s life-cycle assessment platform for semiconductor manufacturing, showed that these infrastructure elements can make a meaningful contribution to the environmental footprint per wafer. It also highlighted substantial uncertainty, as published studies use different system boundaries and rarely report the detailed quantities needed to represent a semiconductor fab accurately.

High-volume semiconductor fabs are also very different from conventional buildings. They combine large concrete and steel structures with specialised cleanroom elements such as partitions, ceilings, and raised floors. They also contain extensive HVAC, electrical, gas, water, and wastewater networks, together with central air-handling, cooling, power, and process-utility equipment. Automated material-handling systems, support buildings, and site infrastructure add further complexity.

This project will develop a modular and traceable life-cycle model covering the physical infrastructure within the boundary of a generic high-volume 300-mm fab. The model will make the environmental impact of fab infrastructure an explicit and quantifiable part of semiconductor life-cycle assessment, allowing infrastructure design choices to be directly linked to their impact per processed wafer.

Objective

The project will build and implement the fab infrastructure model in imec.netzero.. It will cover the main infrastructure elements at a consistent level, with more detail where the environmental impact or uncertainty is highest.

The work will include:

• Setting up a clear structure for the different parts of the fab, including foundations, the building structure, cleanroom fit-out, support buildings, mechanical and electrical systems, water and wastewater systems, central facility equipment, and automated material handling.
• Building the inventory using available data such as floor areas, quantity take-offs, bills of materials, environmental product declarations, supplier information, construction case studies, and internal data.
• Including the main life-cycle stages, from production and construction to replacement, refurbishment, and end-of-life treatment.
• Using parameters such as cleanroom area, total floor area, wafer-start capacity, utility capacity, equipment lifetime, and replacement rate to represent different fab designs.
• Calculating the environmental impact at different levels, including per facility, per square metre, per year, and per processed wafer.

Responsibilities

You will work with the sustainability team and, where possible, cleanroom and facility experts to collect the required data and carry out the LCA.

Your work will include:

• Reviewing relevant studies, technical data, and available internal information.
• Preparing and checking the data used in the LCA.
• Building and running the LCA calculations.
• Analysing the results and identifying the main environmental contributors.
• Supporting the implementation and testing of the model in imec.netzero

Skills and Learning Objectives

Experience with life-cycle assessment is required. Familiarity with construction materials, building services, BIM, quantity take-offs, or environmental product declarations is an advantage.

During the project, you will gain experience in:

• Applying LCA to complex industrial buildings and facilities
• Working with construction and facility data from different sources and levels of detail
• Making and documenting modelling choices when data are incomplete
• Assessing data quality and uncertainty in practical LCA work