A sustainable future for semiconductors

Sustainability is set to become an increasingly important topic within the semiconductor industry. Some large multinational companies, such as Apple, Google and Microsoft, represent important end customers in this business and have already committed to achieving zero emissions for the entire production chain. Consequently, semiconductor manufacturers, which form a substantial part of the supply chain, are also called upon to adopt more sustainable production processes and reduce emissions to meet the demands of their main customers.

The first results of this new orientation are already beginning to be glimpsed. Intel recently committed to zero gas emissions by 2040 and has set an interim goal to use 100% renewable energy by 2030. Another large semiconductor manufacturer, Infineon, plans to reduce greenhouse gas emissions by 70% by 2025 and aims to achieve carbon neutrality by the end of 2030. Over the next few months or years, more and more semiconductor companies are expected to strive to reduce emissions.

In semiconductor factories, most of the emissions are related to the energy needed to run large plants: production lines, high-temperature furnaces, large clean rooms that require climate and humidity control, refrigerators, water purifiers and gas abatement systems.
Other emissions come from the process gases used during wafer engraving, chamber cleaning and other activities. These gases include PFC, HFC, NF3 and N20. They have a high global warming potential (GWP). In addition, the power requirements in manufacturing plants are expected to grow significantly as the size of the chip nodes continues to decrease.

Reducing energy consumption in semiconductor factories can be achieved by replacing existing manufacturing equipment with more energy-efficient tools and by implementing intelligent control systems. Other optimizations may come from the exclusive use of energy from renewable sources, from the greater energy efficiency of the buildings that host the production plants and from the replacement of existing lighting with LED luminaires.

To ensure that sufficient energy is always available, semiconductor companies often use a combination of electricity from the power grid and off-grid sources. Most off-grid energy is generated by fossil-fuel power plants owned by the factories themselves. Semiconductor manufacturers can significantly reduce energy consumption based on these outdated systems and switch to alternative fuels such as biogas or green hydrogen, photovoltaics, fuel cells and battery energy storage systems.

Regarding the electricity grid, companies can choose to purchase renewable electricity. In Europe and the United States, for example, supply from renewable sources is normally available. But in many parts of Asia, procurement can be difficult due to limited availability. Access to renewable energy can become an important factor in choosing where to build the next factories now that efforts are being made to increase production capacity to alleviate the chip shortage through the construction of new semiconductor manufacturing plants.

Process gas emissions vary based on the upgrading level of the facility and the abatement technology used. Semiconductor manufacturers can reduce emissions by adjusting process parameters, such as chamber temperature and pressure. Process engineers often overlook this optimization and instead focus solely on performance. Further emission reductions can result from replacing polluting chemicals with products that have a lower environmental impact.
To reduce gas emissions, manufacturers can also collect and refine unused process gases and by-products through various means, such as membrane separation, cryogenic recovery, sorption and desorption. However, for this recovery to become economically viable, researchers will need to develop more effective technologies for separation of process gas streams and purification.