Small dimension Si wafers are still relevant today – An interview with Sil’tronix ST

As of 2019, the small-size wafer market represents over 63% (in units) of the total wafer market, excluding memory & logic applications. According to Yole Développement (Yole) and its recent report, 6’’ and Below: Small-Dimension Wafer Market Trends 2020, it is forecasted to still represent 53% of the total in 2025.  Although Si is being pushed from its pedestal by non-Si materials such as GaAs, SiC and InP, it still represents almost half of the total sub 6’’ wafer market (US$ 2.2 billion) and will be on par with sapphire in 2025 (US$1.8 billion and US$1.7 billion, respectively). Whether we are talking about low volumes, such as niche or defense applications, or larger ones for regular power devices, such as IGBTs and MOSFETs, sub 6’’ Si wafers are still very relevant in today’s semiconductor industry. There is a “good enough” trade-off here: why move to ever larger diameters when industrial volumes and end-device performance do not justify large equipment/fab CAPEX? Universities, R&D institutes and start-ups/SMEs, all more likely to be constrained by physical and financial resources, also generate significant demand in the sub 6’’ Si market, be it for rapid prototyping or simply for regular production.

Sil’tronix ST is one of the latest Si manufacturers to offer fully customizable 1’’ to 6’’ Si wafers for research and industrial applications. Yole Développement (Yole) recently met with Charly Forteville, Sales Export Engineer at Sil’tronix ST, to discuss today’s small diameter Si ecosystem and Sil’tronix ST’s latest offerings, as well as the company’s roadmap for the years to come.

This interview was conducted by Gaël Giusti, PhD., and Vishnu Kumaresan, PhD., Semiconductors & Manufacturing Market Analysts at Yole.

Gaël Giusti (GG): Could you please introduce Sil’tronix ST, its history, and current activities?

Charly Forteville (CF): Sil’tronix ST was created 40 years ago with the purpose of producing customized Si wafers.

From the beginning the company has been based in the French Alps between the Mont Blanc and Geneva.

Originally, the firm supplied only universities and laboratories. However, with the growth of industrial companies coming from these entities, Sil’tronix ST has developed its portfolio to offer solutions ranging from fundamental research to industrialization.

Since its creation, the company has continuously developed its offerings to propose 3 kind of solutions:

  • Customized silicon wafers from 1” up to 6” for universities, laboratories, and industrials;
  • Specific silicon crystals, mainly for universities and laboratories;
  • A large range of services such as downsizing, SOI downsizing, laser marking, refurbishment of Si wafers and crystals, …

GG: Sil’tronix ST offers fully customized 1’’ to 6’’ Si wafers. According to you, what makes Sil’tronix ST stands out in today’s semiconductor industry?

CF: Sil’tronix ST mainly provides customized Si wafers. This means that we receive the specification from potential users in order to manufacture the wafers accordingly. In addition, we offer volumes in accordance with specific needs: low volumes for fundamental research up to large volumes for industrials, we support our customers all along the TRL system.

In the event the wafers requested have never been manufactured before, we are able to initiate an R&D process to determine how best to meet the specific requirement.

Finally, the size of the company is relevant to our customers, as it gives the ability to discuss specific and key processes with qualified persons.

GG: What markets are you addressing? And which application(s) and market(s) mainly drive(s) Sil’tronix ST’s revenue today?

CF: Sil’tronix ST addresses a wide range of markets from fundamental research up to luxury markets: biology, MedTech, biotech, light source, ion beam, electronics, astronomy, communications, MEMS, sensors, augmented reality (IR), watchmaker, jewelry, …

The sensor and MEMS markets drive our revenue.

GG: Does Sil’tronix ST only work with research institutes and where is your main customer base?

CF: Originally, Sil’tronix ST worked mostly with universities and laboratories. Then, naturally, the company started developing the industrial market. So today, universities and laboratories drive our main customer base with an increasing trend in industrial markets.

This customer mix is really important for Sil’tronix ST in order to be at the heart of technological discoveries and then applying the technology to meet industrial requirements.

Vishnu Kumaresan (VK): Does Sil’tronix ST offer other materials or products than Si wafers? Does the company plan on offering larger Si diameters?

CF: Beside Si wafers, the company provides optical products, such as Zero diffraction plates for XRD, sputtering target, customized silicon crystals as per customer needs as well as their refurbishment.

Furthermore, the production is divided into separate cells, independent of each other. It is the best solution in order to offer the maximum service: we can include or remove an action at each step in the process.

Concerning the diameter of our Si wafers, increasing the dimensions is not currently considered. We focus mainly on the possibility of providing larger specificities and volumes to our customers.

VK: Does Sil’tronix ST offer Si wafer reclaim services? Why not?

CF: Sil’tronix ST offer this service but we do not communicate much about it. The main reason is the volume required. It is generally quite large and we do not have the capabilities to meet to such volumes.

VK: What are the competitive advantages of Sil’tronix ST products?

CF: Sil’tronix ST’s strength lies in the fact that we are manufacturer. As a consequence, the company knows in detail the entire production process and its intricacies, which is really appreciated by our customers.

Every wafer comes from our factory. This provides the insurance of consistent quality across the different orders. It is one of our key success factors for a long-term relationship.

Sil’tronix ST also provides the opportunity to manufacture exotic products, impossible to find otherwise in the market.

Furthermore, in those cases where our customers need to discuss specifics of their requirements, we are able to put them together with our technical department. Depending on the level requested, be it doctors or engineers, technicians from our staff are involved.

In this way we can come to a mutual agreement on how to manufacture the Si wafers or Si crystals as close as possible to what was imagined initially.

In summary, our services in working close to our customers combined with our high technical skills are our competitive advantages.

VK: How do you see the sub 6’’ Si market evolving in the years to come?

CF: Despite the fact that volumes seem to be decreasing in the near future, the specifications will be more challenging and sophisticated. This means there will be greater value per unit than for mass market productions.

VK: Has Sil’tronix ST activity been impacted by the Covid-19 pandemic so far?

CF: Our activity has been impacted by the sanitary lockdown. As soon as the protocol had been implemented, we noticed a global decrease. For a few weeks now things have been improving and we are returning to a standard level of activity.

Images – Legend: Fully customized Si crystal parts as offered by Sil’tronix ST – Courtesy of Sil’tronix ST, 2020


Charly Forteville is Sales Export Engineer at Sil’tronix ST. Holding a master’s degree in international marketing combined with a degree in the electronics field, Charly Forteville used to work for Schneider Electric as a technical sales pilot and marketing assistant. Then, after professional experience with a retailer, he wanted to return to a manufacturing environment. Charly Forteville joined Sil’tronix ST in 2016 to develop the business and marketing activities.


Gaël Giusti, PhD., is a Technology & Market Analyst specializing in Semiconductor Manufacturing and Equipment & Materials at Yole Développement (Yole). As part of the Semiconductor & Software division at Yole, Gaël’s expertise is focused on thin film growth and related applications, equipment, materials and manufacturing processes. He is involved daily in the production of technology & market reports and custom consulting projects. Prior to Yole, Gaël served as a R&D engineer at Sil’Tronix Silicon Technologies for 5 years where he was in charge of upscaling a CVD process to develop epitaxial AlN thin film on sapphire for RF applications. He also worked on transparent conducting thin films for optoelectronics applications as a post-doctoral researcher at LMGP (Grenoble, France). Gaël holds a master’s degree from ENSICAEN (Caen, France) as well as a PhD in Materials Science from the University of Birmingham (UK).

Vishnu Kumaresan, PhD., is a Technology & Market analyst in the Semiconductor Manufacturing Team of Yole Développement, France. He focuses on the semiconductor manufacturing domain, covering both equipment and material segments. His scope includes mainstream microelectronic applications as well as More-than-Moore applications. Having lived and worked in 4 countries, he has more than 11 years of experience in the electronics industry, covering semiconductor, display, and software technologies. Prior to joining Yole, he worked as an epitaxy engineer in an advanced startup in the micro LED display industry and has previously gained corporate experience at IMEC, CNRS, Saint Gobain and Infosys. Vishnu obtained his PhD in Material Physics & Chemistry from Pierre and Marie Curie University, France, and master’s in Microelectronics from National University of Singapore and Technical University of Munich, Germany.

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