Quartz wafers are round, thin substrates cut to semiconductor-industry size conventions — diameter, thickness, polish side count, and edge/flat geometry are all specified together, following SEMI-adjacent sizing rather than a general L×W×thickness spec.
Standard Diameters
| Diameter | Inch Designation |
|---|---|
| 25.4 mm | 1 inch |
| 50.8 mm | 2 inch |
| 75 mm | 3 inch |
| 100 mm | 4 inch |
| 150 mm | 6 inch |
| 200 mm | 8 inch |
(4 inch and larger: “inch” = 25.0mm per wafer industry convention; 1–2 inch: “inch” = 25.4mm)
Thickness Examples by Diameter
| Diameter | Typical Thickness | Tolerance |
|---|---|---|
| 1 inch | 500 µm | ±20 µm |
| 2 inch | 200 µm | ±25 µm |
| 3 inch | 500 – 1000 µm | ±25 µm |
| 4 inch | 200 – 1500 µm | ±25 – 50 µm |
| 4 inch (semiconductor grade) | — | ±10 µm thickness tolerance, diameter ±0.3mm |
| 6 inch (semiconductor grade) | — | ±10 µm thickness tolerance, diameter ±0.3mm |
Surface & Geometry
| Parameter | Specification |
|---|---|
| Polish | Single-side (SSP) or double-side (DSP) |
| Surface roughness | Ra <0.5 – 1 nm on polished side |
| TTV (total thickness variation) | <1 – 10 µm depending on grade |
| Bow / warp | <30 – 60 µm depending on diameter |
| Edge / flat | SEMI standard flat (e.g. 32.5mm on 4-inch), or no-flat round edge per drawing |
| Edge exclusion | 6 mm typical (measurement/process keep-out zone at the wafer edge) |
Material Options
- Fused silica / fused quartz (amorphous, no crystal orientation) — standard for semiconductor process/carrier wafers
- Crystal quartz (X-cut, Y-cut, Z-cut, ST-cut, AT-cut) — for piezoelectric/frequency-control applications where crystal orientation matters
- Semiconductor-grade quartz: low CTE (0.59 ppm/K), low OH content, for high-temperature process compatibility
Application
Semiconductor and MEMS process/carrier wafers, thin-film deposition substrates, photonics and frequency-control (crystal-cut) applications, dummy/test wafers for equipment calibration.
FAQ
Do I need crystal quartz or fused silica/quartz wafer?
Fused silica/quartz (amorphous) for general process, carrier, or optical substrate use — no crystal orientation to specify. Crystal quartz (X/Y/Z/ST/AT-cut) only if you need its piezoelectric properties, e.g. for frequency-control devices.
What edge geometry should I specify?
SEMI standard flat if your equipment/handling expects it; no-flat round edge otherwise — confirm against your process tool requirements.
Can wafers be supplied as rectangular pieces instead of round?
Yes — square/rectangular pieces cut from wafer stock are available, though separation costs mean it’s usually only economical at meaningful order quantities.