Semiconductor Insiders - Podcast EP331: Soitec’s Broad Impact on Quantum Computing and More with Dr. Christophe Maleville

Episode Date: February 13, 2026

Daniel is joined by Dr. Christophe Maleville, Chief Technology Officer and Senior Executive Vice-President of Soitec’s Innovation. He joined Soitec in 1993 and was a driving force behind the company’s joint research activities with CEA-Leti. For several years, he led new SOI process development, oversaw SOI technology transfer… Read More

Hello, my name is Daniel Nenny, founder of semi-wiki, the Open Forum for Semiconductor Professionals. Welcome to the Semiconductor Insiders podcast series. My guest today is Dr. Christoph Malvel, Chief Technology Officer and Senior Executive Vice President of Soytek's Innovation. He joined Soytek in 1993 and was a driving force behind the company's joint research activities with C-EA Leti. For several years, he led new SOI process development, oversaw SOI technology. transfer from R&D to production and managed customer certifications. He also served as vice president, SOI Products Platform at Soytek, working closely with key customers worldwide.

He has authored or co-authored more than 30 papers and also holds 30 patents. Welcome to the podcast, Christoph. Thank you. Nice to you. First, I'd like to ask, what brought you to Soytek in 1993? A series of opportunities, I would say. And at that time, as a young engineer, I was looking for PhD to be done. And Chelle Bruel, that invented the smart cut originally, was looking for a PhD student

that would be interested in carrying some wafer bonding and layer transfer studies in the, for the SOI application. Well, I decided at the time that looked at very interesting applied research type of topic. I was really looking for something that would bring me to the clean room and learn a lot into the semiconductor processing steps. So I joined that PhD thesis together with Soytek and Letty. And then I, well, I never left the project somehow. Then I joined Soitech. It was 12 people at that time. We grew that SOI process for some time. I was then process engineer and then well you know the company has been growing and I've been

growing with the company having different type of jobs from process engineers development leader product VP as we are growing with business units and business unit leader sales manager site manager and then at some point that well I said you've been here for a while and we need the CTO that knows the technology and the business side of it and so I embarked for the CTO job, and that's my job as of today. So it's been 33 years and still super excited into all these opportunities of our engineered substrates. Oh, that's a great story.

We've been working with Soytek for several years, and it's been a pleasure. There's been so many events we participated in, so active in the ecosystem. So let me ask, what does the industrial availability, of 28 SI FDSOI Wafers enabled for quantum computing that was not possible before. I mean, why is this such an important milestone for scalable silicon-based quantum processors? Yeah, that's a great question that is embarking

a lot of dimensions of what Soit can do with engineers of trades. And if we look at the global end results, the industrial availability of 28SRIs, FDSY waferes bring something that was not possible before the access to this isotopically purified silicon with the control specification. But to understand, first in the quantum computing application, we have to bring this isotopically purified silicon, which is kind of the only grail for spin-based quantum computing. the customers are taking an electronic way of building a qubits and the reason is that

the 28 silicon this isotope is eliminating the noise that kills the cubits. Standard silicon we have mostly 29 silicon that isotopes create some magnetic impacts for the quantum information. So you have to see that around the atom, there is this magnetic field that is creating some magnetic noise that is impacting the electrons. Because the natural silicon is about 5% of these 29 silicon isotope with the nuclear spin. And these spins, we have to see that they are acting like very tiny, wondering.

magnet slip and drop and defacing the electron spin cubits. By using this isotopically purified 28 silicon, we create a semiconductor vacuum that has zero nuclear spin, and the cubit can live in a magnetically quiet environment, which is extending the coherence time by orders of magnitude, and this is so important for the quantum computing information. So So what we do is typically the usual approach that we have in So It takes. So we looked at the challenge for the quantum computing companies that are doing the qubits by electronics. And we've been working with Coalick on that topic. And they explained us this issue with the silicon.

And so we then looked at how we can integrate these pure means 99.999% layers of, silicon with this special isotope and integrate that into a fully depleted SOI substrate, which then can enable to have these very efficient electronics built on the FDSOI. When I say there's multiple elements, the fully depleted SOI is another element of our technologies. So not only we are integrating this special silicon in it, but also we are putting it in our special fully depleted solid SOI. Fully depleted refers to the ultra-fined silicon layer that we are bringing on top of an embedded oxide, buried oxide into the layer. And this creates a confinement, a natural geometry confinement for the electrons. Typically the layer is less than 10 nanometer. And so with

the oxide in the bottom, we can access not only from the top, which is the conventional way of building a device by putting a gate on top of this ultra-fine silicon. But with the oxide on the bottom, we can also access from the backside, which is enabling the designers to build a back gate. And it gives a unique lever to tune the electrical environment of the qubits and the threshold voltage of the surrounding CMOS, across. bios I would say because it's done at low temperature which allows to control the circuits independently and the last thing is well we are doing that on a conventional base of a 28 nanometer at the SOI

which is done with ST and this is already operating in large volume with a great control of the uniformities of the process parameters into the into the the fab and by implementing this specific isotop of the silicon to a pre-existing manufacturing line, then we are accelerating the path to high-volume manufacturing for a quantum computing application. Oh, interesting. So why is validating these wafers inside ST microelectronics 300 millimeter fabs such a critical step

in moving quantum technology from R&D to real-world applications? As I a little bit said, but let me deploy a little more that answer. While running these waferes in a 300 millimeter fab, it's giving us access to process control, already established, learning cycles already made, and characterization infrastructures that are typically

not available in a research clean room. So we get more statistics and a much lower noise in terms of the viability, which is accelerating the learning. This is what allows Copley to design quantum devices with industrial constraints in mind. And that from the very beginning. But we have to understand that building a qubit is something that is now accessible from multiple technologies.

We have been working some different type of SOI to work with different customers in photonics type of SOI. And here, when I talk about this 28 silicon, about electronics-based quantum qubits. But in a real world, the application, they require 100 to thousands of perfect qubits. Usually people call logical qubits. Technologically, it means quality and yield of the qubits at million scales that are provided by the quality of the wafer and the quality of the fab. We need to have mature substrate entering the fab, but also a mature yield and reproducibility in terms of the process.

And this is why being able to introduce engine and substrate that are specifically modified for the quantum application into a fab that is already running large volume of FDSOI wafer. It's a key milestone for quantum industry. And that's what we can put together with Soyttec wafers into ST micro fab. From a European perspective, how does this milestone strengthen Soyttex role within the continent's emerging quantum ecosystem? So we had at the European level and within the groundable local ecosystem, we had multiple communication recently showing this time with Kobliu, and as I said, we have also other customers behind. But that project here demonstrates not only a credible, but also, a time-bound path towards million qubit systems, which is necessary conditions for quantum computers to deliver the real, I would say,

industrial value or application value. And the simple idea is making qubits using the same industrial principles that have enabled some other semiconductor industry to scale transistors. So here we add this opportunity together with Orano, air liquid STM and Kobli and Soitech to provide this unique FDSOI Silicon 28 wave which provides EU with a worldwide leading silicon-based quantum computer ecosystem. And that's been showing also the commitment and the importance of industry or semiconductor industry in the development of quantum computing solutions.

Typically, we read a lot about research around quantum computing in the lab But here we have to understand that the real breakthrough is that we are directly upgrading some existing seamless devices with a quantum level into the fab. And so it's clearly accelerating the path to volume. And clearly, in the bringing from the lab to the fab, we are directly putting the lab in the fab, I would say, by upgrading the substrate that we are launching

into a mature device line. And this is done here in Europe, so that's super important in what we're doing. And that's very so important from a so it takes standpoint to be able to tune that device, that substrate, sorry, directly into a mature ecosystem. From my experience, Soitech is known for focusing on industrialization rather than isolated breakthroughs. So how does that mindset shape your approach to innovation in emerging technologies like quantum computing? That's a very interesting point and that's typically in the daily mindset of my team in the way we drive the innovation and the way we are managing our innovation.

And this is also linked to the maturity of the company. For a long time, we've been looking at how you push the limits and demonstrate some unique substrates and unique capabilities, showing a cross-section of the type of layers that that we can implement together. And while growing and having more partnership with the customers, we clearly move to two types of mindset in terms of the innovation, design to cost and design to manufacturing. Design to cost more linked to some consumer application,

I would say. In the quantum computing space, we are not talking to design to cost per se now, but this design to manufacturing gets very, very important. And as a conclusion of wrap-up of the previous questions that we have, we clearly think about the substrate as a design to manufacturing, meaning what we implement has to be compatible with the large volume in the fab. And even though this is a special wafer that we will have a few of them run into the fab, they have to be compatible. with the large volume manufacturing, and especially they have to be compatible with the yields and the maturity that's required to build these 100,000 qubits

on the few ways that are going to be run. Interesting. So why is building an end-to-end integrated European value chain central to Switech's long-term innovation strategy? What are you trying to accomplish here? I would say that that can be said it's a strategic preference for Soyttec, but not only, it's also a fundamental requirement when industrialization,

industrializing destructive technologies and also contributing to the technological sovereignty in Europe. I would say we view this integrated approach in terms of typically three different critical lenses. One is we want to accelerate the path from the lab to the market. And this innovation in material science, like our smart-set process, will only be valuable if it can be manufactured at scale. So by coordinated pan-European consortions, we can reach the gap between early-stage research and high-volume industrial impact. And I have a couple of examples of what has been done into Europe.

We had a program called Move to TerraEF where we led a 27-member consortium to build a very robust European supply chain for indium phosphide, targeting 6G and AI data centers. Another example will be Beyond 5. This is a project where there was 37 partners to structures a full European supply chain for RFSOI, enabling new domains of 5G and 3G and 3.5. sensing. And the last example I'd like to bring into this acceleration is what we call soil. That's a work with 38 partners where we talked about FDSOI, but here we are securing FDSOI value chain from the material to the system for automotive and H. AI. So going from this European partnership, again, we have really the full supply chain validated. from the research to the final system. That's so important, of course, in the path volume.

The second lens is strategic autonomy and resilience, of course. Few years ago, we remember there was a global chip crisis which highlighted how fragile or fragmented our supply chain can be. And working on an integrated European value chain is aiming to ensure a kind of a virtual cycle. have a virtual cycle from innovation, from substrate design to foundries like ST microelectronics to end-user like Bosch. And this has to be remained within a secure and autonomous ecosystem. I think this can be seen as reducing the dependency to non-EU suppliers, protect our core

competencies in strategic market segments, but overall to bring some very strategic parts into the overall worldwide supply chain, where then we can have some very balanced conversation overall from Europe to the rest of the world. And I think that's very key. The last lens is the co-innovation for complex systems. In the modern technological challenge we have in front of us, such as silicon carbide for electric vehicles or quantum computing,

we talked about it. This requires deep collaboration across the entire value chain. And if I retain the smart SIC or the silicon carbide example, we had a transformed project in Europe where we could partner with Bosch and other to build a trusted European Silicon Carbite value chain and validate and ensure that our substrate were perfectly tuned for the next generation power modules. So this end-to-end integrated European projects and initiatives are very key to accelerate

accelerate, validate, secure the solutions we are providing. I agree completely. Final question, Christoph, advanced engineering substrates sit at the core of Soyttex portfolio, and they're very important in the industry. How does this milestone illustrate Soytek strategy of using substrate innovation as a long-term platform to enable new technology waves, such as quantum computing?

I think it's back to the way we are really defining our innovation and the way we are defining our engineers substrates. We like to integrate in our engineering substrate the materials innovation, the material contribution that is enabling, impacting positively our daily life. So this milestone, this talk about quantum computing we are today, it's a clear example. And we talked about it. How do we look at what has to be the... final solution and how we integrate that on our substrate, looking at the as fast as

possible as immediate as possible application into the volume by making sure that this material we are bringing into the structure of our substrate can directly fit with the requirements of the substrate that are used in a volume application but delivering the the final impact the final benefit into the substrate. Another point point also is we like to look at the sustainability as a driver. And when we combine this 28 silicon with FDSOI, we are quite happy to bring together not only a coherent solution for the quantum computing, but also a low power solution.

And by upgrading a proven solution like the FDSOI in ST, in ST, we are also bringing a sustainable solution in terms of the power consumption and in terms of the CO2 emission that is reduced through this device, but also that is reduced through the mature supply chain we are doing. Indeed, with our smart cut process, we are reusing multiple times, this donor wafer, and that's so important in terms of the total CO2 emission that we can lower into this very advanced solution. So it really sits at the core as a summary of Soitech. We are really proud to bring this new material into a special substrate that really then goes into a mainstream solution,

but also making sure that we do that in protecting the planet. Great. That's a pleasure to speak with you, Gerov. Thank you for your time. And it's also a pleasure to work with Sooytech on these new innovations. So hopefully we can meet next time you're out in Silicon Valley. I hope so. Yeah, it would be a great pleasure. Thank you very much. That concludes our podcast. Thank you all for listening and have a great day.