Semiconductor Manufacturing on the Way to Net Zero

As chip production increases, so do carbon emissions. European semiconductor companies have made sustainable commitments and set ambitious emission-reduction targets, but will they be sufficient to achieve net zero by 2050?

Infineon CEO Jochen Hanebeck solemnly broke ground on the company’s new 300-mm Smart Power Fab in Dresden, the capital city of the German state of Saxony, in early May.

“We are speeding up for the green and digitization transition of Europe and beyond,” Hanebeck said in his address at the groundbreaking ceremony. “The demand for semiconductors is growing strongly and persistently in view of the high demand for renewable energies, data centers and electromobility. We are increasing our production capacity significantly and shall produce analog, mixed-signal and power semiconductors.”

The urgent need to strengthen sustainability efforts comes at a time when semiconductor production is increasing to meet sustained demand, and advanced chips with greater computing power or storage capacity are required.

In a follow-up discussion at the groundbreaking ceremony, Rutger Wijburg, Infineon COO and member of the management board, told EE Times Europe, “We’ve set ourselves the target of being carbon neutral by 2030, and if we look ahead to 2025, we’re already 70% of the way there.” The chipmaker expects to reduce its CO2 emissions by 70% by 2025 compared with 2019.

Wijburg acknowledged that achieving the last 30% will be the most difficult to achieve, but said that “in this new facility, we’ll put all the most modern techniques in place in order to recycle energy and water. This will be the most efficient fab.”

Powering fabs with renewable energy

The global semiconductor manufacturing industry is set to double its market size in terms of revenue by 2030, with some sectors, such as electric vehicles (EVs), expected to grow relatively faster than others. It is also expected to consume 237 terawatt hours (TWh) of electricity globally in 2030, close to Australia’s 2021 electricity consumption, according to environmental group Greenpeace.

One of the key steps toward achieving semiconductor sustainability is using renewable energy sources. Over the years, many semiconductor companies have expanded their green energy supply, some even investing in their own renewable energy infrastructure.

In 2022, Infineon consumed 2,568 gigawatt hours (GWh) of energy worldwide. Within its manufacturing sites, the front-end sites consume most of the energy, especially when establishing the highly stable climatic conditions of cleanrooms.Semiconductor Manufacturing on the Way to Net Zer

The World Semiconductor Council (WSC) has defined electricity consumed per square centimeter manufactured wafer as the unit for measuring the energy efficiency of front-end sites. Compared with the global average value of the WSC, Infineon’s front-end sites worldwide used about 53% less electricity to manufacture one square centimeter wafer in 2021, the company said in its latest sustainability report.

When asked whether Infineon is using renewable energy, Wijburg replied with an assertive “yes.”

“We use green electricity, not only in Germany but also in the United States where energy is very cheap relative to Europe,” he said. “We still find it very important that we are leading as a company in carbon neutrality, and our facility in the United States is purchasing green electricity.”

Achieving the net-zero goal first requires companies to identify how they buy, use and track energy.

In 2021, Infineon switched to purchasing 100% green electricity for its manufacturing sites in Europe. In May 2022, its manufacturing site in Austin, Texas, followed suit, and Infineon completed the switchover to green electricity in the U.S. by the end of 2022. The company aims to be 100% on renewable power globally by 2025.

“If I look today at the Infineon fabs compared to the average semiconductor fabs, in terms of energy usage or water consumption, we are everywhere on the lower part of the distribution, and in a number of cases, we are actually 50% lower than the average,” Wijburg said. “To produce our chips, we are using energy. But if you look at the amount of CO2 that we emit to produce those chips and the amount of energy that we save with our products over their lifetime, it is an effect of one to 33. It’s not enough, but it’s impressive.”

Speaking more specifically about Infineon’s €5-billion (about $5.3 billion) Smart Power Fab in Dresden, he said, “We want to take the new fab to the next level and put more measures in place in order to become the most efficient fab towards carbon neutrality in 2030.”

Reducing, reusing, recycling

“Water, not chips”: This was the message on some placards carried by peace demonstrators outside the STMicroelectronics (STMicro) Crolles plant in early April. The demonstrators were protesting the 300-mm fab announced last summer by STMicro and GlobalFoundries, which they associate with excessive water consumption.

Water is a limited natural resource, and manufacturing semiconductors requires a large volume of water to cool equipment or to generate ultra-pure water.

In its 2023 Sustainability report, STMicro reported it had reduced its water consumption per unit of production by 12% in 2022 compared with 2016. Its ambition is to improve its water efficiency by 20% by 2025. In 2022, STMicro said its water recycling rate reached 42%, a 2-point increase compared with 2021, and expects to reach its goal of 50% by 2025. All wastewater is treated before being discharged into the environment.

The semiconductor industry uses many chemicals and materials that are hazardous to the environment. It also generates tons of non-recyclable waste every year.

In an interview with EE Times Europe, CEA-Leti CEO Sébastien Dauvé provided some context: “The digital industry is being strongly challenged not only on its own energy consumption, but also on its ability to provide more sustainable solutions, and foundries themselves are also being strongly challenged today on their consumption of water, energy, gas, etc.”

CEA-Leti said it has joined SEMI’s Semiconductor Climate Consortium to collaboratively tackle such environmental challenges. As part of its Eco-innovation plan, it has also incorporated a variety of tasks as part of its manufacturing execution.

In 2021, the research institute said it recycled 20% of ultra-pure water and reduced electricity consumption for air recycling by 15%. It is also targeting reductions in solvents and gas use and improved recovery and recycling strategies for materials.

Developing a green mindset

Green engineering is a mindset of innovation through which engineers continuously challenge themselves to do more with less. CEA-Leti has adopted a sobriety approach, which aims to maximize performance with a given budget or limited resources. It also encourages its researchers to think differently, taking into account life-cycle analysis—from design to application—and not just on a performance/cost analysis.

“For many of our projects, we carry out a life-cycle analysis to quickly identify either critical materials that we’re going to try to replace or technological choices that turn out to have a much lower carbon impact, whether in terms of production or use,” Dauvé said. “We’ve started publishing on this subject, and we’ve come up with some interesting results on the design of a beam-forming antenna. We’ve proposed an architecture based on a technology that’s a little different from what’s usually done—and which makes it possible to impact the overall life cycle of these antennas. This has really created momentum among our in-house teams.”

CEA-Leti has also implemented the concept of application technology co-optimization. It aims to enhance the end-of-life management of electronic devices, as well as the relevant databases to ensure life-cycle analyses and improve optimization of the environmental impact at the system and usage level.

When asked about employees’ intrinsic green motivation, Dauvé said, “We can sense it, engineers and researchers are very keen to take concrete action, and I’d say it’s starting to become a habit in our innovation practices.”

Attracting talent with green credentials

More than a million additional skilled workers will be needed to meet demand in the semiconductor industry by 2030, according to a Deloitte report. As competition for talent intensifies, how can companies make the difference?

A sense of purpose has become one of the strongest arguments for attracting talent, and green credentials have become a must.

At a 2022 press conference in Paris, Paul Boudre, then-CEO of Soitec, said, “We are determined to be a role model in sustainability for several reasons: The first one is our responsibility towards the planet and the second is our responsibility towards our employees. It’s important to show them the purpose of the company. When you have the level of growth we have, you have to be able to grow talent faster. You have to be able to attract people and retain them.”

In 2021, Soitec joined the Science-Based Targets initiative—which is led by CDP Worldwide, the World Wildlife Fund, the World Resources Institute and the United Nations Global Compact program—and adopted the trajectory limiting global warming to 1.5°C above pre-industrial temperatures.

Sustainability is not only part of corporate social responsibility, but also a critical element of workforce strategy, Dauvé said.

“There’s a global [talent] bottleneck,” he added “At Leti, we’ve taken this issue seriously, with some concrete actions. The Next-Gen FD-SOI 10-nm project gives us the opportunity to create an attractive ambition. We have the capacity to recruit several dozen people for this project. We were afraid that we wouldn’t be able to recruit and that we wouldn’t have any candidates. In the end, we have candidates, both young and older, who are very interested in the technological ambitions we are proposing. As part of this recruitment process, we are introducing new methods to better train our new recruits.”

FD-SOI is an ultra-low-voltage technology able to operate down to 0.4 V at minimum energy per operation. It has been a key research and development area for over 20 years at CEA-Leti.