To find out how imec intends to help improve the sustainability of chip production, EE Times Europe met with Emily Gallagher, program director for imec's sustainable semiconductor technologies and systems program.
www.eetimes.eu/, Jul. 09, 2024 –
Imec has developed a virtual platform to assess the impact of different choices taken during the chip manufacturing process. The Leuven, Belgium–based research institute is currently examining the possibility of creating a safe data space to share carbon footprint information.
To find out how imec intends to help improve the sustainability of chip production, EE Times Europe met with Emily Gallagher, program director for imec's sustainable semiconductor technologies and systems (SSTS) program, at ITF World 2024.
Gallagher immediately put the discussion in context with a reminder of how successful the global chip market has been. Total global revenues nearly reached $600 billion in 2021–and they're on track to exceed 1 trillion by 2030. "Looking at global emissions in 2021, we were at 37 billion tons, and the semiconductor industry had about a half-percent of that, at 185 million tons," she said. "That's a big contribution to global warming."
According to Gallagher, fabless companies were ramping up for Scope 3 reporting in 2021 and quickly realized they didn't have all the information they needed. One thing that was missing was insight into the semiconductor carbon footprint. Solving this problem was a primary reason why imec started the SSTS program in 2021.
"We started the program in collaboration with supply chain partners–including fabs, material suppliers and companies that make the equipment used to manufacture chips," Gallagher said. "The program also interacts with academia, industry associations and governments, because sustainable solutions demand engagement throughout the ecosystem."
The SSTS program developed a tool called imec.netzero that serves as a virtual fab. It models a generic high-volume manufacturing (HVM) fab to assess the impact of different options taken in the processes that go into IC chip manufacturing. Users select different fab options, and the model uses preconfigured, bottom-up, process-level data–including process equipment, consumable materials and process flows–to quantify the resulting IC chip footprint.
Public and private versions with varying degrees of data sharing
A public version of the model is open for anybody to use. Private versions are made available only to partners–and typically, each partner uses its own version with protected data space. When using the private version, a partner can input data that won't be shared. Likewise, that same partner can't see the private data input by a different organization. Herein lies the challenge of taking the virtual fab to the next level. The tool cannot be used for official validation for reporting purposes unless it has access to real data for all relevant equipment and processes. But for what the tool does now, which is to help organizations improve their process, an approximation of any missing data does just fine.
"None of the OEM suppliers want the details of their process tools to be communicated," Gallagher explained. "So instead, we create tool models using a combination of our own fab data and input from partners. Whether in practice a technology uses an etch system from Applied Materials, Lam Research or Tokyo Electron, we're able to provide a representative process to incorporate into the process flows and predict environmental impact."
The public version, which is available at netzero.imec-int.com, is less granular and includes fewer technologies but provides general insight into the environmental impact of semiconductor manufacturing using the same virtual fab models as the partner versions.
Imec uses its own private version to guide its internal development priorities. Gallagher provided an example of how imec used its private version to make some of its processes more environmentally friendly. In this case, imec homed in on the lithography scanner, which for advanced logic nodes accounts for most of the Scope 2 emissions associated with energy use. Using the life-cycle analysis principles, imec was able to look at the lithography scanner holistically–including data on input process materials, energy consumption and waste.
"We examined different choices we could make and saw the impact of each of them," Gallagher said. "We have partnerships with two industry leaders in this area: ASML for lithography scanners and Edwards for abatement and vacuum. We were able to test a hydrogen-recovery system to reuse hydrogen from the EUV scanner source. This is purified so it can be reintroduced to the lithography source. In the end, we've been able to reuse over 10 million standard liters of hydrogen."
Official validation of carbon footprint will require more data sharing "The advantages of this bottom-up methodology are that we have the granularity to identify challenging steps in the process - and target them for improvement," Gallagher said. "We can identify the impact of different choices and path find to guide future node decisions. Our model includes the combustion process gas and fugitive emissions for Scope 1, electricity emissions for Scope 2 and then the embodied upstream material emissions and disposal for Scope 3." The idea of joining forces across the value chain to find more sustainable solutions continues to attract big players. Just yesterday, imec announced its newest member - none other than Intel Corp. Nevertheless, the biggest remaining obstacle is reminiscent of the "Tragedy of the Commons" scenario in game theory: Until each of the players has an incentive to fully share numbers, the greatest good will never be achieved. While the tool has already proven its value for analyzing the impact of different choices, in its current state, it cannot be used for official validation of carbon footprint for reporting purposes. According to Gallagher, the program has received a lot of requests to do so, and they are looking for ways to make this possible. The challenge standing in the way of official validation is that very few organizations want to share their data - and for good reason. Very few companies want to give away proprietary numbers that might be used against them, by competitors or regulators. Or is there another solution? "We are exploring options for creating a safe data space to share carbon footprint information in a verifiable way for the semiconductor industry," Gallagher said.