Glass is considered to be a good material, enabling consumer electronics to be produced even thinner. It helps make possible the high-performance computing necessary for applications and enables higher performance in mobile devices.
Glass material for semiconductor applications has been analyzed in-depth by the market research and strategy consulting company, Yole Développement (Yole). Their team has published a dedicated technology & market report, Glass Substrate for Semiconductor Applications 2020.
Today, the scope for applications using glass substrates in the semiconductor field is broad and highly diversified.
Glass material can support various functionalities within IC devices in the semiconductor field, such as actuators, MEMS and sensors, CMOS Image Sensors (CIS), memory and logic, Radio Frequency (RF), power electronics, photonics, microfluidics devices as well as the Fan-Out Wafer-Level Packaging (FO WLP) technology platform. It can be structured in different ways:
- Permanent support glass substrates that undergo many fabrication process steps, such as etching, deposition of materials, and photolithographic patterning;
- Wafer-Level Capping (WLCapping), which is based on mechanical sawing of a wafer cap above the sensor;
- 3D TGV/Glass interposer, referring to a structure integrating vertical through via electrical connections from top to underside, Through-Silicon-Vias (TSVs) for interposers or Through-Glass-Vias (TGV) for glass interposers;
Level Optics (WLOptics), split into two main wafer-level elements:
- Refractive optical elements based on lens structures, so-called Wafer-Level-Lenses;
- Diffractive optical elements (DOE), including microoptics for Augmented Reality (AR);
- Infra-red (IR) cut-off filters processed on panel substrates, where the purpose is to keep IR separate from CMOS devices that are sensitive to infra-red;
- Glass carriers are also used as temporary substrates to provide mechanical support for thin silicon device wafers.
From a market point of view, the demand for glass material was almost 4M 8-inch eq wafers in 2019 and is expected to reach nearly 9.5M 8-inch eq wafers by 2025, driven by FO WLP and microfluidics as well as CIS applications.
Indeed, the use of glass carriers, which are already used for FO WLP and Power devices, is expected to experience rapid growth. However, it is negligible in terms of revenue due to the high recyclability of 8-inch glass carrier, and demand for the glass material remains a considerable fraction of the market in wafer starts. Also, as the glass carrier can be recycled several times, we expect glass material to have an adoption rate of more than 90% in the industry by 2025. Glass carriers for FO WLP will have the highest growth rate in the 2019-2025 period reaching more than 3.3 M glass wafer 8-inch eq.
Another key driver encouraging power manufacturers to use glass carriers in their process is the ability to inspect the temporary bonding results through the glass wafer by visual inspection due to the high transparency of the glass material.
The only reason to use a Si substrate as a carrier comes from people’s fear. They do not want to risk using a foreign material that could contain contents that may lead to contamination. However, alkali-free glass is available in the market and is mostly used for glass carrier functionality.
Therefore, the type of debonding process and cleaning determines the re-use – not the material, be it glass or Si.
Memory applications will also participate in the growth of the glass wafer market driven by the adoption of glass carriers.
Key memory manufacturers have been evaluating laser debonding equipment since 2015, technology that requires the use of glass carriers. They still have some concerns about integrating glass carriers in their process, as ‘alkali-free’ still contains up to 0.1% alkali ions and thus could lead to contamination in their fabs. As a consequence, with qualification taking at least 2 years, this brings the earliest possible date for mass production of glass carriers for memory to early 2023.
When it comes to the competitive landscape, the number of glass vendors able to deliver wafers and panels within industry specifications is limited.
The top two players, Schott and Corning, have led the glass material market for the last few years, holding more than 60% of the total glass wafer market.
However, other glass raw material and glass wafer processor vendors, such as NEG, AGC, PlanOptik, and Tecnisco, have already captured a share of this market.
NEG’s market share comes from the FO WLP market since it is the leading supplier to TSMC for the inFO product. PlanOptik’s revenues account for the majority of the business for glass carriers for power applications due to its relationship with Infineon for actuator MEMS pressure sensors using WLCapping.
There are still business opportunities in an immature market that are not really well established that could reshuffle the ranking by the entrance of specialized glass vendors with well-honed expertise in specific applications. Although Corning and AGC are very active in the RF front-end and connectivity industry with their borosilicate products, the RF industry is evaluating photosensitive glass material that is mostly offered by 3D Glass Solutions.
Their solutions could be an alternative for RF high-frequency applications due to its high thermal performance combined with low-cost manufacturing.
The level of performance & the cost will determine the winners.
About the author
Amandine Pizzagalli is a Finance Project Manager at Yole Finance, part of Yole Développement (Yole). Amandine oversees financial consulting and advisory services, including M&A, capital raising, IPO definition, valuation & financial analyses…
She works closely with Ivan Donaldson, Senior Vice President of Yole Finance.
Previously, Amandine was a member of the development team in Yole’s Semiconductor & Software division. She focused on the development of comprehensive analyses dedicated to semiconductor equipment, materials industries, and all semiconductor manufacturing processes.
Amandine also worked as a Process Engineer on CVD and ALD processes for semiconductor applications at Air Liquide. She was based in Japan for a year to manage these projects.
With an extensive knowledge of the semiconductor supply chain, she has spoken in numerous international conferences and has authored or co-authored more than 10 papers.
Amandine holds an international MBA from IAE Lyon, School of Management (France) and an electronic engineering master’s degree from the engineering school, CPE Lyon (France), with an added degree focusing on semiconductor manufacturing technology from KTH Royal Institute of Technology (Sweden).
The glass substrate market has $200M revenue today and will triple over the next five years, driven by Fan-Out Wafer Level Packaging (FO WLP), CMOS Image Sensors (CIS) and microfluidic devices.
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