Samuel Okay. Moore Hello. I’m Samuel Okay. Moore for IEEE Spectrum‘s Fixing the Future podcast. Earlier than we begin, I need to let you know which you can get the newest protection from a few of Spectrum‘s most necessary beats, together with AI, local weather change, and robotics, by signing up for one in every of our free newsletters. Simply go to spectrum.ieee.org/newsletters to subscribe. The semiconductor trade is within the midst of a serious enlargement pushed by the seemingly insatiable calls for of AI, the addition of extra intelligence in transportation, and nationwide safety issues, amongst many different issues. Governments and the trade itself are beginning to fear what this enlargement may imply for chip-making’s carbon footprint and its sustainability typically. Can we make all the things in our world smarter with out worsening local weather change? I’m right here with somebody who’s serving to determine the reply. Lizzie Boakes is a life cycle analyst within the Sustainable Semiconductor Applied sciences and Techniques Program at IMEC, the Belgium-based nanotech analysis group. Welcome, Lizzie.
Lizzie Boakes: Howdy.
Moore: Thanks very a lot for coming to speak with us.
Boakes: You’re welcome. Pleasure to be right here.
Moore: So let’s begin with, simply how large is the carbon footprint of the semiconductor trade? And is it actually large enough for us to fret about?
Boakes: Yeah. So quantifying the carbon footprint of the semiconductor trade is just not a simple process in any respect, and that’s as a result of semiconductors at the moment are embedded in so many industries. So the obvious trade is the ICT trade, which is estimated to be about roughly 3 % of the worldwide emissions. Nonetheless, semiconductors can be present in so many different industries, and their embedded nature is rising dramatically. In order that they’re embedded in automotives, they’re embedded in healthcare purposes, so far as aerospace and protection purposes too. So their enlargement and adoption of semiconductors in all of those completely different industries simply makes it very arduous to quantify.
And the worldwide affect of the semiconductor chip manufacturing itself is anticipated to extend as properly due to the truth that we want an increasing number of of those chips. So the worldwide chip market is projected to have a 7 % compound annual progress price within the subsequent coming years. And making an allowance for that the manufacturing of the IC chips itself typically accounts for the most important share of the life cycle local weather affect, particularly for shopper electronics, as an illustration. This improve in demand for therefore many chips and the demand for the manufacturing of these chips can have a major affect on the local weather affect of the semiconductor trade. So it’s actually essential that we concentrate on this and we establish the challenges and attempt to work in the direction of lowering the affect to attain any of our ambitions at reaching internet zero earlier than 2050.
Moore: Okay. So the best way you checked out this, it was type of a— it was cradle-to-gate life cycle. Are you able to type of clarify what that entails, what that actually means?
Boakes: Yeah. So cradle to gate right here signifies that we quantify the local weather impacts, not solely of the IC manufacturing processes that happen contained in the semiconductor fab, but in addition we quantify the embedded affect of the entire vitality and materials flows which are coming into the fab which are mandatory for the fab to function. So in different phrases, we attempt to quantify the local weather affect of the worth chain upstream to the fab itself, and that’s the place the cradle begins. So the extraction of the entire supplies that you simply want, the entire vitality sources. For example, the extraction of coal for electrical energy manufacturing. That’s the cradle. And the gate refers back to the level the place you cease the evaluation, you cease the quantification of the affect. And in our case, that’s the finish of the processing of the silicon wafer for a selected know-how node.
Moore: Okay. So it stops mainly while you’ve acquired the die, but it surely hasn’t been packaged and put in a pc.
Boakes: Precisely.
Moore: And so why do you’re feeling like you need to take a look at all of the upstream stuff {that a} chip-maker might probably not have any management over, like coal and such like that?
Boakes: So there’s a large want to investigate your scope by means of what is named— in greenhouse gasoline protocol, you’ve got three completely different scopes. Your scope one is your direct emissions. Your scope two is the emissions associated to the electrical energy consumption and the manufacturing of electrical energy that you’ve got consumed in your operation. And scope three is mainly all the things else, and lots of people begin with scope three, all of their upstream supplies. And it does have— it’s clearly the most important scope as a result of it’s all the things else aside from what you’re doing. And I believe it’s essential to coordinate your provide chain so that you simply ensure you’re doing probably the most sustainable resolution which you can. So if there are— you’ve got energy in your buying, you’ve got energy over the way you select your provide chain. And should you can manipulate it in a means the place you’ve got diminished emissions, then that must be completed. Usually, scope three is the most important proportion of the full affect, A, as a result of it’s one of many greatest teams, however B, as a result of there’s a number of supplies and issues coming in. So yeah, it’s mandatory to take a look up there and see how one can greatest cut back your emissions. And yeah, you’ll be able to have energy in your affect over what you select ultimately, by way of what you’re buying.
Moore: All proper. So in your evaluation, what did you see as type of the largest contributors to the chip fabs carbon output?
Boakes: So with out efficient abatement, the processed gases which are launched as direct emissions, they might actually dominate the full emissions of the IC chip manufacturing. And it is because the processed gases which are typically consumed in IC manufacturing, they’ve a really excessive GWP worth. So if you don’t abate them and you don’t destroy them in a small abatement system, then their emissions and contribution to international warming are very massive. Nonetheless, you’ll be able to drastically cut back that emission already by deploying efficient abatements on particular course of areas, the high-impact course of areas. And should you try this, then this distribution shifts.
So then you definately would see that the direct emission– the contribution of the direct emissions would cut back since you’ve diminished your direct emission output. However then the next-biggest contributor could be {the electrical} vitality. So the scope to the emissions which are associated to the manufacturing of the electrical energy that you simply’re consuming. And as you’ll be able to think about, IC manufacturing could be very energy-intensive. So there’s a number of electrical energy coming in, so it’s mandatory then to attempt to begin to decarbonize your electrical energy supplier or cut back your carbon depth of your electrical energy that you simply’re buying.
After which when you try this step, you’d additionally see that once more the distribution modifications, and your scope three, your upstream supplies, would then be the most important contributors to the full affect. And the supplies that we’ve recognized as being probably the most or the most important contributors to that affect could be, as an illustration, the silicon wafers themselves, the uncooked wafers earlier than you begin processing, in addition to moist chemical compounds. So these are chemical compounds which are very particular to the semiconductor trade. There’s a number of consumption there, they usually’re very particular and have a excessive GWP worth.
Moore: Okay. So if we may begin with— unpack a couple of of these. First off, what are a few of these chemical compounds, and are they often abated properly today? Or is that this type of one thing that’s nonetheless a coming drawback?
Boakes: Yeah. In order that they could possibly be from particular photoresists to— there’s a very heavy consumption of fundamental chemical compounds for neutralization of wastewater, these kinds of issues. So there’s a mixture of getting in a excessive embedded GWP worth, which signifies that it takes a really great amount of– or has a really massive affect to supply the chemical itself, otherwise you simply have loads that you simply’re consuming of it. So it might need a low embedded affect, however you’re simply utilizing a lot of it that, ultimately, it’s the upper contributor anyway. So you’ve got two form of buckets there. And yeah, it will simply be a matter of, you need to multiply by means of the quantities by your embedded emission to see which of them come on high. However yeah, we see that usually, the wastewater therapy makes use of a number of these chemical compounds only for neutralization and therapy of wastewater on website, in addition to very particular chemical compounds for the semiconductor trade equivalent to photoresists and CMP cleans, these forms of very particular chemistries which, once more, it’s tough to quantify the embedded affect of as a result of typically there’s a proprietary— you don’t precisely know what goes into it, and it’s a number of issue making an attempt to truly characterize these chemical compounds appropriately. So typically we apply a proxy worth to these. So that is one thing that we would love to enhance sooner or later could be having extra communication with our provide chain and actually understanding what the true embedded affect of these chemical compounds could be. That is one thing that we actually would want to work on to actually establish the high-impact chemical compounds and take a look at something we will to scale back them.
Moore: Okay. And what about these direct greenhouse gasoline emission chemical compounds? Are these typically abated, or is that one thing that’s nonetheless being labored on?
Boakes: So there’s fairly, yeah, a considerable quantity of labor going into the abatement system. So we have now the same old methane combustion of processed gases. There’s additionally now improvement in plasma abatement programs. So there are completely different abatement programs being developed, and their effectiveness is kind of excessive. Nonetheless, we don’t have such a superb oversight in the intervening time on the quantity of abatement that’s being deployed in high-volume manufacturing. This, once more, is kind of a delicate subject to debate from a analysis perspective while you don’t have perception into the fab itself. So asking specific questions on how a lot abatement is deployed on sure instruments is just not such straightforward information to come back throughout.
So we frequently go together with fashions. So we apply the IPCC Tier 2c mannequin the place, mainly, you calculate the direct emissions by how a lot you’ve used. So it’s a mathematical mannequin based mostly on how a lot you’ve consumed. There’s a mannequin that generates the quantities that may be emitted immediately into the environment. So that is the mannequin that we’ve utilized. And we see that, yeah, it does correlate typically with the top-down reporting that comes from the trade. So yeah, I believe there’s a number of means ahead the place we will begin evaluating top-down reporting to those bottom-up fashions that we’ve been producing from a form of analysis perspective. So yeah, there’s nonetheless a number of work to do to match these.
Moore: Okay. Are there any specific nasties by way of what these chemical compounds are? I don’t suppose individuals are acquainted with actually what comes out of the smokestack of chip fab.
Boakes: So one of many highest GWP gases, as an illustration, could be the sulfur hexafluoride, so SF6. This has a GWP worth of 25,200 kilograms of CO2 equal. So that actually signifies that it has over 25,000 occasions extra damaging results to the local weather in comparison with a CO2, so the equal CO2 molecule. So that is extraordinarily excessive. However there’s additionally others like NF4 that— these even have over 1,000 occasions extra damaging to the local weather than CO2. Nonetheless, they are often abated. So in these abatement programs, you’ll be able to destroy them they usually’re now not being launched.
There are additionally efforts going into changing excessive GWP gases equivalent to these that I’ve talked about to make use of options which have a decrease GWP worth. Nonetheless, that is going to take a number of course of improvement and a number of effort to enter altering these course of flows to adapt to those new options. And this may then be a sluggish adoption into the high-volume fabs as a result of, as we all know, this trade is kind of inflexible to any modifications that you simply counsel. So yeah, it is going to be a sluggish adoption if there are any options. And for the meantime, efficient abatement can destroy rather a lot. However it will actually be having to make use of and actually have these abatement programs on these high-impact course of areas.
Moore: As Moore’s Regulation continues, every step or manufacturing node might need a distinct carbon footprint. What have been a few of the large developments your analysis revealed concerning that?
Boakes: So in our mannequin, we’ve assumed a relentless fab operation situation, and which means we’ve assumed the identical abatement programs, the identical electrical carbon intensities, for the entire completely different know-how nodes, which– yeah. So we see that there’s a normal improve in whole emissions underneath these assumptions, and we double in whole local weather affect from N28 to A14. So once we evolve in that know-how node, we do see it doubling between N28 and A14. And this may be attributed to the elevated course of complexity in addition to the elevated variety of steps, in course of steps, in addition to the completely different chemistries getting used, completely different supplies which are being embedded within the chips. This all contributes to it. So typically, there is a rise due to the method complexities that’s required to actually attain these aggressive pitches within the extra superior know-how nodes.
Moore: I see. Okay. In order issues are progressing, they’re additionally form of getting worse in some methods. Is there something—?
Boakes: Yeah.
Moore: Is that this inevitable, or is there—?
Boakes: [laughter] Yeah. For those who make issues extra sophisticated, it’s going to most likely take extra vitality and extra supplies to do it. Additionally, while you make issues smaller, you must change your processes and use– yeah, as an illustration, with interconnect metals, we’ve actually reached the bodily limits typically as a result of it’s gotten so small that the bodily limits of actually conventional metals like copper or tungsten has been reached. And now they’re searching for new options like ruthenium, yeah, or platinum. Several types of metals which– once more, if it’s a platinum group metallic, after all it’s going to have the next embedded affect. So once we hit these limits, bodily limits or limits to the present know-how and we have to change it in a means that makes it extra sophisticated, extra energy-intensive— once more, the transfer to EUV. EUV is an especially energy-intensive device in comparison with DUV.
However an attention-grabbing level there on the EUV subject could be that it’s actually necessary to maintain this holistic view as a result of although transferring from a DUV device to an EUV device, it has a big soar in vitality depth per kilowatt hour. The ability depth of the device is way increased. Nonetheless, you’re in a position to cut back the variety of whole steps to attain a sure deposition or edge. So that you’re in a position to total cut back your emissions, otherwise you’re in a position to cut back your vitality depth of the method stream. So although we make all these modifications and we would suppose, “Oh, that’s a really highly effective device,” it may go and reduce down on course of steps within the holistic view. So it’s at all times good to maintain a form of life cycle perspective to have the ability to see, “Okay, if I implement this device, it does have the next energy depth, however I can cut back half of the variety of steps to attain the identical outcome. So it’s total higher. So it’s at all times good to maintain that form of holistic view once we’re doing any kind of sustainability evaluation.
Moore: Oh, that’s attention-grabbing. That’s attention-grabbing. So that you additionally checked out— as type of the nodes get extra superior and processes get extra complicated. What did that do to water consumption?
Boakes: Additionally, so once more, the variety of steps in the same sense. For those who’re rising your variety of course of steps, there could be a rise within the variety of these moist clear steps as properly which are typically the high-water-consumption steps. So you probably have an elevated variety of these specific course of steps, then you definately’re going to have the next water consumption ultimately. So it’s simply based mostly on the variety of steps and the complexity of the method as we advance into the extra superior know-how nodes.
Moore: Okay. So it feels like complexity is form of king on this subject.
Boakes: Yeah.
Moore: What ought to the trade be specializing in most to attain its carbon objectives going ahead?
Boakes: Yeah. So I believe to start out off, you must consider the most important contributors and prioritize these. So after all, should you’re trying on the whole affect and we’re a system that doesn’t have efficient abatement, then after all, direct emissions could be the very first thing that you simply need to attempt to concentrate on and lowering, as they might be the most important contributors. Nonetheless, when you begin transferring right into a system which already has efficient abatement, then your subsequent goal could be to decarbonize your electrical energy manufacturing, go for a lower-carbon-intensity electrical energy supplier, so that you’re transferring extra in the direction of inexperienced vitality.
And on the identical time, you’d additionally need to attempt to goal your high-impact worth chain. So your supplies and vitality which are coming into the fab, you must take a look at those which are probably the most extremely impacting after which attempt to discover a method to discover a supplier that does a form of decarbonized model of the identical materials or attempt to design a means the place you don’t want that sure materials. So not essentially that it needs to be completed in a sequential order. In fact, you are able to do all of it in parallel. It will be higher. So it doesn’t must be one, two, three, however the concept and the prioritizing comes from focusing on the most important contributors. And that may be direct emissions, decarbonizing your electrical energy manufacturing, after which your provide chain and looking out into these high-impact supplies.
Moore: Okay. And as a researcher, I’m certain there’s information you’d like to have that you simply most likely don’t have. What may trade do higher about offering that form of information to make these fashions work?
Boakes: So for lots of our a number of our scope three, in order that upstream, that cradle-to-fab, let’s name it— these impacts. We’ve had to make use of rather a lot— we needed to rely rather a lot on life cycle evaluation literature or life cycle evaluation databases, which can be found by means of buying, or typically should you’re fortunate, you’ve got a free database. So I might say– and that’s additionally as a result of my function in my analysis group is extra that LCA and upstream supplies and quantifying the environmental affect of that. So from my perspective, I actually suppose that this trade must work on offering information by means of the provision chain, which is standardized in a means that individuals can perceive, which is product-specific in order that we will actually allocate embedded affect to a selected product and multiply that by means of then by our stock, which we have now information on. So for me, it’s actually having a standardized means of speaking sustainability affect of manufacturing, upstream manufacturing, all through the provision chain. Not solely tier one, however all the best way as much as the cradle, the start of the worth chain. So that is something– and I do know it’s evolving and it is going to be sluggish, and it does want a number of cooperation. However I do suppose that that may be very, very helpful for actually making our work extra real looking, extra consultant. After which individuals can depend on it higher after they begin utilizing our information of their product carbon footprints, as an illustration.
Moore: Okay. And talking of type of your work, are you able to inform me what imec.netzero is and the way that works?
Boakes: Yeah. It is a net app that’s been developed in our program, so the SSTS program at IMEC. And this net app is a means for individuals to work together with the mannequin that we’ve been constructing, the LCA mannequin. So it’s based mostly on life cycle evaluation, and it’s actually what we’ve been speaking about with this cradle-to-gate mannequin of the IC-chip-manufacturing course of. It tries to mannequin a generic fab. So we don’t essentially level to any particular fab or course of stream from a sure firm. However we attempt to make a really generic trade common that individuals can use to estimate and get a extra real looking view on the fashionable IC chip. As a result of we seen that, in literature and what’s out there in LCA databases, the semiconductor information is extraordinarily previous, and we all know that this trade strikes in a short time. So there’s a enormous hole between what’s occurring now and what’s going into your telephones and what’s going into the computer systems and the LCA information that’s out there to attempt to quantify that from a sustainability perspective. So imec.netzero, we work with all of— we get pleasure from being linked with the trade and now a place in IMEC, and we have now a view on these extra superior know-how nodes.
So not solely do we have now fashions for the nodes which are being generated and produced at the moment, however we additionally predict the long run nodes. And we have now fashions to foretell what’s going to occur in 5 years’ time, in 10 years’ time. So it’s a extremely highly effective device, and it’s out there publicly. We’ve a public model, which is a limited– it has restricted performance compared to this system associate model. So we work with our program companions who’ve entry to a way more sophisticated and, yeah, deep means of utilizing the net app, in addition to the opposite work that we do in our program. And our program companions additionally contribute information to the mannequin, and we’re continuously evolving the mannequin to enhance at all times. In order that’s a little bit of an summary.
Moore: Cool. Cool. Thanks very a lot, Lizzie. I’ve been talking to Lizzie Boakes, a life cycle analyst within the Sustainable Semiconductor Applied sciences and Techniques Program at IMEC, the Belgium-based nanotech analysis group. Thanks once more, Lizzie. This has been unbelievable.
