A substrate is quartz cut and finished to carry a functional layer — a coating, a deposited film, a sensor structure — where flatness and surface finish are the primary spec, in a format (round or rectangular) chosen to fit your equipment rather than a standard wafer size series.
Dimensions
| Parameter | Specification |
|---|---|
| Format | Round (diameter) or rectangular (L × W), per drawing |
| Thickness | Per drawing |
| Flatness | Per drawing — tighter than general plate stock where coating/deposition uniformity matters |
| Surface | Polished (single or double side) to the roughness your process requires |
Substrate Types by Function
| Type | Use |
|---|---|
| Optical substrate | Light transmission or optical performance is the priority — polished to optical-grade flatness/roughness |
| Carrier/dummy substrate | Structural or equipment-support function, calibration and thermal/process testing — flatness matters less than mechanical stability |
| Process substrate | Deposited-film or coating base — surface roughness and cleanliness are the priority |
Material Grade
JGS1 commonly selected when UV transmission performance matters more than visible/IR behavior; see the Quartz Glass Tubes Material Grades table for the full comparison. Drawing-based supply for special thickness, geometry, and edge-processing requirements not covered by standard wafer sizing (see Quartz Wafers for the SEMI-adjacent size series).
Packaging
Protective clean wrapping, foam isolation, and reinforced outer cartons standard to reduce edge damage during shipping.
FAQ
What’s the difference between a substrate and a wafer?
Wafer usually implies a standard round semiconductor-industry size (1–8 inch series). Substrate is broader — round or rectangular, sized to your equipment or application rather than a standard series.
Do I need an optical substrate or a carrier/dummy substrate?
Optical substrate if light transmission or optical performance through the part matters. Carrier/dummy substrate if it’s providing structural or process-testing function without an optical requirement.