Glass Carrier Wafer and Glass Carrier Panel

Glass Carrier

The semiconductor industry uses glass carrier wafers to streamline processes such as 3D IC packaging, wafer thinning, and fan-out wafer-level packaging (FO-WLP). The carrier wafers, which are essential during manufacturing, bond with semiconductor wafers to facilitate safe handling and minimise damage.

What are glass carrier wafers?

Glass carrier wafers are precisely manufactured discs made of thin glass materials such as borosilicate and alumino-borosilicate. These materials are selected for their excellent thermal expansion properties and transmittance. Manufactured using advanced technology, the wafers meet stringent quality standards and are tailored to suit the specific requirements of the industry. 

Why glass is ideal for semiconductors

In semiconductor manufacturing, carrier wafers and panels play a critical role. The advantages of glass over other materials include excellent thermal stability, which allows them to withstand high temperatures during processing without deformation. The stability of a glass carrier minimizes mechanical stress and maintains the integrity of the wafer during critical manufacturing steps. The diverse thermal expansion rates of available glasses also allow for optimal adaptation to various semiconductor materials, simplifying processing. Additionally, the high light transmission of glass aids precise optical inspections, essential for quality control. Together, these properties make glass an indispensable material for efficient and reliable semiconductor production.

Advantages of glass carrier

Glass carriers are becoming increasingly important in the fast moving world of semiconductors. This is due to the following key properties:

High raw glass quality

High reproducibility of our melting processes ensures high and consistent quality of raw glass.

High raw glass quality

Broad CTE range

This allows a range of materials to be placed as carrier wafers during semiconductor processing, with a closely matched CTE for optimal results.

Broad CTE range

Mechanical robustness

Excellent processing performance of carrier wafers results in extraordinary robustness in areas such as breakage strength.

Mechanical robustness

Chemical and high temperature resistance

Glass is an excellent material for carriers thanks to its high resistance to acids and other chemicals, as well as its excellent thermal shock properties.

Chemical and high temperature resistance

Transparency

The transparency of glass carriers enables a laser debonding process and allows in-process inspection. It also facilitates the identification of any bonding problems that may occur.

Transparency

Extremely low tolerances

Carrier wafers offer a TTV level of ≤ 3µm, enabling superior silicon wafer thinning and a warpage of ≤ 50µm, avoiding higher warpage during the layer stacking process.

Extremely low tolerances

Form and shape

Glass is ideal as a carrier substrate as it offers fewer size limitations. Produced as a wafer, it has the same notch and chamfer geometry options as silicon wafers, with the added benefits of glass.

Forms and Shapes

Cost-effective and durable

Thanks to its superior properties, glass carrier wafers and panels can be used up to 10 times, increasing the sustainability of these critical components while decreasing costs.

Cost-effective and durable

Ready for back-end processes

Glass carriers enable silicon wafer/die handling in semiconductor production.

Ready for back-end processes

Broad choice of materials for glass carrier to fit customers requirements

SCHOTT glass portfolio with a broad CTE range to meet customer device materials due to our broad choice of materials we can fulfil our customers requirements.
Graph showing the CTEs of a variety of SCHOTT glasses

Geometrical properties of SCHOTT Glass Carrier

Geometrical properties Value

Ultra Low Total Thickness Variation (TTV)

< 2.0 µm (Standard)
< 0.5 µm (Advanced)

Precise Thickness Tolerances

± 5.0 μm (Standard)
± 2.5 μm (Advanced)

Warp (Depending on materials and thicknesses)

  8'' < 30 µm
12'' < 50 µm

 Cosmetic Quality (Depending on materials and thickness)

Scratch/Digs:
40/20 (Standard)
20/10 (Advanced)

Bonding and debonding of glass carrier

High UV transmittance allows temporary bonding and debonding
Graph showing the optical transmission of SCHOTT Glass Carriers

Spectral transmittance: thickness 1.1 mm for λ = 250 nm to 400 nm

Graph showing the optical transmission of SCHOTT Glass Carriers200-500 nm-EN

Spectral transmittance: thickness 1.1 mm for λ = 200 nm 500 nm

SCHOTT Glass Carrier can be delivered as follows:

  • Flat/notch: According to SEMI standard
  • Laser marking: According to SEMI standard, T7, QR-Barcode/unique number
  • Cleaning: Ultra/mega-sonic cleaning and cleanroom ISO 6
  • Packaging: Inspection and packaging under ISO 6 in wafer boxes (FOSB, RTU, etc.)