Development of Substrates Featuring Through Glass Vias ( TGV ) for 3 DIC Integration
Citation
Authors: Aric Shorey, Scott Pollard, Alex Streltsov, Garret Piech, Robert Wagner
Partial Title: Development of Substrates Featuring Through Glass Vias (TGV) for 3D-IC Integration
Keywords
- Through Glass Vias (TGV)
- 3D-IC Integration
- Glass Substrates
- Fusion Process
- CTE (Coefficient of Thermal Expansion)
- Wafer Strength
- Via Formation
- Cost-effectiveness
- Corning Incorporated
Brief
This article discusses the benefits of using glass as a substrate material for Through Glass Vias (TGV) in 3D-IC integration due to its customizable properties and cost-effectiveness.
Summary
This article explores the potential of Through Glass Vias (TGV) as a promising alternative to silicon in 3D-IC integration. Glass, with its adaptable properties and cost-effectiveness, offers a compelling solution for creating high-performance and scalable substrates.
Here are the key takeaways from the article:
- Glass Properties: Unlike silicon, glass is not a single material but a diverse group with a wide range of properties that can be tailored by adjusting its composition. This allows for customization of mechanical, thermal, and electrical characteristics to meet specific application requirements.
- Fusion Forming Process: Corning's fusion process emerges as a superior method for manufacturing thin and pristine glass wafers. This method results in a smooth surface without the need for costly and time-consuming polishing or thinning procedures. This process makes scaling up production easier and enhances substrate reliability. The fusion process also allows for the production of wafers in various sizes, including large formats up to 450mm.
- Strength and Reliability: While glass and silicon wafers demonstrate comparable median strength, glass exhibits more consistent and predictable strength due to the absence of flaws introduced during grinding and polishing. The article emphasizes the importance of minimizing flaws during via creation to maintain the overall strength and reliability of the TGV substrates.
- Via Formation: Numerous techniques, including mechanical, chemical, and laser-based methods, can create through-holes in glass for TGV. However, challenges remain in terms of scalability, achieving smooth sidewalls for mechanical reliability, cost optimization, and throughput.
- Advantages of TGV: The article concludes that glass substrates with TGVs hold significant potential for 2.5D-IC and 3D-IC applications. Key advantages highlighted include:
- The ability to tailor glass properties to meet specific application needs.
- The use of the fusion process which ensures excellent surface quality, low warp and TTV, and flexibility in substrate size and thickness.
- Cost advantages and improved economies of scale due to the elimination of finishing steps.
- Future Challenges: The authors acknowledge that the primary challenge in advancing TGV technology lies in developing cost-effective methods for creating holes in glass with the required size, shape, quality, and reliability.