Sustainability isn’t a new concept to the semiconductor industry, but only now have officials begun getting a big picture view of the industry’s impact on the environment and how well it is doing at getting greener.
The formation of the Semiconductor Climate Consortium (SCC) has formalized what many companies in the industry were already doing, and the recent release of its report on carbon emissions is the first comprehensive study to span the entire value chain, including end user device consumption, chip manufacturing processes, and energy grids. The SCC is governed by SEMI, the industry association serving the global electronics manufacturing and design supply chain.
In an interview with Fierce Electronics, Mousumi Bhat, VP of sustainability programs at SEMI, said previous reports only touched on one segment of the industry, but in collaboration with the Climate Change Disclosure Program, the consortium now has a rich set of data that paints a more holistic picture. “It's one of the most comprehensive studies that you'll find,” she said.
A key piece of data is that the semiconductor industry used 340 terawatt hours of electricity in 2022 – the equivalent of about 1.3% of global demand, Bhat said, and that percentage is growing. The international target set by the consortium was to achieve net-zero carbon emissions by 2050. These targets are aligned with the 1.5 degree Celsius global-warming target in the Paris Agreement of 2016.
The first sustainability milestone comes in 2025, when chip-industry emissions should peak and decline steadily, Bhat said. One aspiration is to bring emissions to half of the 2019 level by 2030.
There were also a couple of surprises, she said. “We did find that downstream product use has a very large carbon footprint, which needs to be addressed.” The report also found that more than 80% of the industry’s emissions across scope 1, 2 and 3 can be addressed through clean, low carbon energy. Bhat said this is valuable insight because it helps the SCC and the industry define its next call to action.
Scope 1 emissions are the direct emissions that come from sources owned or controlled by the organization, and hence the easiest to get a handle on. Scope 2 emissions are indirect ones resulting from generation or consumption energy purchase by the organization – electricity, heat, steam, and cooling.
Scope 3 emissions are indirect – greenhouse gas emissions that are outside of an organization’s direct control, spanning across the entire lifecycle of a product, including emissions of supply chain partners and customers.
Ultimately, you can’t make chips without using energy, and the things that use chips – everything from smartphones to massive data centers – all consume power. Reducing that consumption has positive side effects for the environment in a variety of ways, including less water use and less materials waste.
Consumers drive rebound effect
Downstream product use is the result of over consumption, Bhat said, or what is called the “rebound effect.” Consumers think that because they are buying more efficient devices, they can buy more devices, she said, but until the energy grid is completely clean, the carbon footprint continues to grow.
Bhat recently witnessed the rebound effect in action at a conference where all attendees were told the available power supply chargers for their laptops were solar-powered. The announcement prompted everyone to pull out their devices to charge them, she said, “even the folks who were not planning to charge their laptops.”
The likely result is that conference had a cumulatively higher footprint than it needed to be, Bhat said. “It's something that we don't think about. It's how the consumer behavior works.”
As chips get more advanced, costs are driven down and efficiencies improve, she said, and there is a general tendency for people to upgrade their phones every year or buy that latest gadget. That consumption pattern is driving semiconductor industry growth, Bhat said. “We need to decouple the rate at which our industry is growing with the rate at which we are decarbonizing the value chain.”
Meanwhile, the migration to a digital economy combined with intense artificial intelligence (AI) and machine learning makes servers more power hungry, Bhat said. “All of that adds to the overall carbon footprint.”
Determining manufacturing’s carbon footprint
Wafer fabrication and packaging are the two largest elements of the manufacturing segment in the value chain. Bhat said 21% of the industry’s total carbon footprint is from manufacturing.
She added that the carbon footprint for manufacturing is greatly dependent on whether it’s connected to a clean or dirty energy grid. “We're obviously a very global industry and a sector very dependent on how the local renewable energy profile shapes up.”
Aside from the carbon footprint from powering manufacturing facilities, Bhat said there’s also opportunities to switch gases that are used in manufacturing processes. “That's where there is quite a bit of research going on,” she said. “It is not very easy to replace a lot of these gases.”
On the materials front, the semiconductor industry has room for improvement – it’s not a big contributor to the circular economy as only just over 9% of materials extracted from nature are recirculated back, and Bhat said it’s dropping. “There's a large opportunity there to improve our circularity index and to improve our emissions.”
Chipmaking requires many materials, including silicon wafers, gas, and chemicals, as well as a great deal of water. Implementing circular economy principles through process optimization and waste reduction lowers the environmental footprint involved in chipmaking, as does recycling of the end products when they reach the end of their life.
Small changes have significant impact
Making the semiconductor sector more sustainable could be seen as many small wins adding up to big strides. Making a chip that consumes less energy adds up when you consider how many of them populate servers in a data center. Sustainability is further compounded by using “cleaner materials.”
Robert Mears, founder and CTO of Atomera, sees the company’s Mears Silicon Technology (MST) as being inherently green. It consists of layers of a non-semiconductor, such as oxygen, inserted into a semiconductor material, such as silicon, so that epitaxial growth is preserved. Over the longer term, it breaks down into sand, he said.
The challenge is to balance the trade offs from using cleaner materials while still getting the desired characteristics and a technology that can scale. Atomera is applying its MST to planar memory and other planar devices at advanced nodes where there’s an opportunity to address standby power, including sensors, Mears said. “We believe that you could save more than 50% of the standby power.”
Even a 10% reduction in power consumption in any semiconductor adds up to a huge amount of savings, he said, especially when you consider how much electricity consumption can be attributed to data centers and computers globally. “You're talking about huge amounts of potential energy saving in this technology.”
Dion Harris, head of data center product marketing at Nvidia, said the overall goal of getting better performance generation over generation is always done with concerned effort to attain improved performance within the same power envelope, if not lower. He said the company’s “accelerated computing” approach has shifted the per watt dynamic in the data center. “We pioneered this whole approach around using GPUs to not just speed up the application, but to give you more performance per watt.”
Performance per watt matters in the data center
Harris said accelerated computing is domain specific, which means there are examples across different workloads. A high-performance computing (HPC) system may see as much as 20 times better energy efficiency, for example.
He said the path forward in the data center is accelerated computing using a GPU in concert with CPUs to optimize the overall performance per watt profile – the energy efficiency makes the data center greener.
Harris said the shift to the accelerating computing paradigm means there’s a dramatic reduction in wattage needed to do train inference models because fewer nodes are needed. These reductions also translate into the less real estate, and hence less cooling. “You're actually able to deliver the same performance within the smaller envelope in terms of power as well as in terms of overall server counts,” he said.
Fewer components also mean fewer materials, which is another way that doing more computing with fewer GPUs is greener. Harris said Nvidia does a lot of taping out now with virtual simulations, which reduces the company’s own environmental footprint. “We're eating our own dog food here,” he said. “We built a very robust process to ensure that we leverage digital simulation for all of our production and for all of our design and manufacturing.”
Reducing water usage is just as critical as lowering power consumption, whether it’s for cooling of data centers or in the manufacturing process. Harris said by allowing customers to get better performance per watt, it also gives them better performance per gallon of water. “It’s a very tightly coupled narrative,” he said.
Looking at greener ways to power data centers is also a key part of making them more sustainable. In Iceland, there’s a concerted effort to take advantage of geothermal energy as part of an initiative led by Data Centers by Iceland to attract businesses who need data centers to support the AI and HPC boom. The heat generated by data centers could even be used to warm nearby businesses and create a sustainable, looped system, even as data centers move to renewable energy.
Micron Technology has had a formal strategy in place for its sustainability efforts for several years now, and Marshall Chase, director of sustainability, has been focused on greening the semiconductor sector a lot longer. “We set our first big picture corporate-wide environmental goals about three years ago.” Those goals are focused on energy usage, emissions, water use and waste, he said.
Water and waste seem to get less attention, Chase said, but the nature of semiconductor manufacturing means a lot of water is used. “We're very sensitive to where we're using it, how we're using it and that we're returning it in as high quality as possible.” He said Micron’s goal is to achieve a 75% water reduction, recycling, and community restoration rate. “There's always going to be some losses and some quality degradation in any industrial system.”
Collaboration is critical to sustainability success
Micron has several ongoing water projects in collaboration with the community of Boise, Idaho, where the company is headquartered, Chase said, as well as others in Virginia and associated with its operations in Taiwan and Singapore.
It’s also collaborating in an ongoing pilot project that compares Aqua Membranes’ Printed Spacer Technology and a standard reverse osmosis (RO) with traditional mesh element architecture at Micron’s Boise fab. Results to date have found that the Printed Spacer Technology components in Micron’s RO water treatment systems reduced energy consumption by more than 20%.
Chase said Micron has also made inroads when it comes to diverting waste from landfills with a target of 95%. “We've been knocking that one out of the park.”
But it’s not been easy, Chase said. Micron has bunch of teams actively pulling on levers associated with sustainability, especially energy. “Renewable energy isn't necessarily available in certain places around the world.” But its new facilities in the U.S. are part of a strategy of using 100% renewable energy for the company’s U.S. operations.
“These are industry-wide challenges and if Micron solves this problem for ourselves, that would be great,” Chase said. But Micron won’t be able to replace the challenging assets that it has in its systems now unless it's something that multiple companies can adopt, he said. “We have to find solutions at scale, otherwise they won't be cost effective.”
Chase said the SCC plays a key role in solving the challenges faced by the industry, including energy use, availability of energy and the impact of manufacturing processes. “These aren't challenges that are unique to Micron.”
SEMI’s Bhat said the value of the SCC’s first report is that it’s an “inside-out narrative” by people in the industry, making it more authentic than an interpretation of the industry by an external party. “The level of quantification here is more robust,” she said. “We own the data. We are telling our own story and we're going to solve our own problems.”