What are glass carrier wafers?
Glass carrier wafers are precision disks of thin glass, such as borosilicate glass and alumino-borosilicate glass. They are created by selecting an appropriate high-quality glass material and then carefully cutting and shaping it.
Why glass is ideal for semiconductors
Used throughout the semiconductor industry, carrier wafers and carrier panels are commonly used to manufacture essential components such as 3D ICs and FO-WLP. In order to withstand the high temperatures required for semiconductor manufacturing, carrier wafers and panels are usually made using a material with high thermal stability.
Carrier wafers date back to the earliest days of semiconductor manufacturing. Initially, the manufacturing process used silicon wafers as carriers, but materials such as glass and ceramics were later introduced. Glass is now a common substrate for carrier wafers and is increasingly important in the fast-moving world of semiconductors for a number of reasons.
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.
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.
Excellent processing performance of carrier wafers results in extraordinary robustness in areas such as breakage strength.
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.
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.
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.
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.
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.
Ready for back-end processes
Glass carriers enable silicon wafer/die handling in semiconductor production.
Broad choice of materials for glass carrier to fit customers requirements
G1, G2 are alkaline free materials
G1, G2 and G3 carriers match Si - wafer CTE
G5 and G6 meet high CTE of compound and other interface material
Geometrical properties of SCHOTT Glass Carrier
Ultra Low Total Thickness Variation (TTV)
≤ 3µm (Standard)
Precise Thickness Tolerances
± 10 μm (Standard)
Warp (Depending on materials and thicknesses)
≤ 50µm (Standard)
Cosmetic Quality (Depending on materials and thickness)
SCHOTT Glass Carrier can be delivered as follows:
- Flat/notch: According to SEMI standard
- Laser marking: 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.)