How Much Does a 300mm Silicon Wafer Weight?
When engineers ask “How much does a 300 mm Silicon Wafer weigh?”, they usually want a number that helps with tooling load limits, robot end-effector tuning, cassette logistics, and shipping design. The key point is that wafer weight is not a fixed constant—it depends primarily on thickness and (to a smaller extent) edge profile and special processing.
The fast answer
A typical 300 mm (12-inch) single-crystal silicon wafer commonly falls into the 725–775 µm thickness range, and that usually puts the wafer mass at roughly 120–130 g per wafer when calculated from geometry and silicon density.
How to calculate wafer weight accurately
A silicon wafer is essentially a cylinder:
Diameter (D): 300 mm = 30 cm
Radius (r): 15 cm
Thickness (t): depends on spec (convert µm to cm)
Silicon density (ρ): about 2.33 g/cm³
Formula
Weight (g) ≈ ρ × π × r² × t
Because r is fixed for 300 mm wafers, thickness is the lever that moves weight the most.
Typical 300 mm wafer weights by thickness
Below is a practical reference table you can use for planning handling and shipping. Values are calculated using ρ = 2.33 g/cm³.
| 300 mm thickness | Thickness (cm) | Estimated wafer mass |
|---|---|---|
| 500 µm | 0.0500 | ~82 g |
| 675 µm | 0.0675 | ~111 g |
| 725 µm | 0.0725 | ~121 g |
| 775 µm | 0.0775 | ~128 g |
Practical note: real wafers may vary slightly due to tolerance, edge shaping, and material removal from polishing, but for manufacturing planning these estimates are usually close enough to size robots, carriers, and freight calculations.
Why wafer weight matters in real manufacturing workflows
Wafer weight is not just a trivia number—it affects cost and yield drivers across the line:
Robot stability and breakage risk: heavier wafers increase inertial load during high-speed transfers, especially when combined with thinness and brittleness. That influences end-effector design and motion profiles.
Process equipment tuning: wafer mass interacts with chucking, vacuum stability, and thermal response during process steps.
Packaging and shipping design: the wafer’s weight plus cassette/FOUP and cushioning design determines drop-test performance and vibration sensitivity, which is why many suppliers publish packing solutions and shipping guidance.
Which specifications change the weight (and what they signal)
If you are defining a 300 mm wafer for production, these spec choices affect the final mass and how it behaves:
Thickness selection: thicker wafers are generally more robust in handling; thinner wafers can support downstream thinning or packaging goals, but demand tighter handling control.
Flatness and thickness uniformity requirements: parameters like Bow, Warp, and TTV don’t change mass much, but they strongly impact tool compatibility and yield, especially in lithography and advanced processes.
Polish level and surface finish: polishing removes small amounts of material, but more importantly it sets the surface condition required for your process window.
Working with Plutosemi for 300 mm wafer supply
From a manufacturer’s perspective, wafer weight discussions usually lead to a bigger question: “Can the supplier hold the full specification consistently?” Plutosemi positions its offering around semiconductor substrate supply plus process-oriented services—helpful when your project requires more than a standard catalog wafer.
When requesting a quote (including bulk order planning or OEM-ready programs), it helps to share:
Diameter and target thickness (and tolerance window)
Crystal type and orientation requirements
Surface finish and polish side requirements
Flatness/TTV targets and inspection expectations
Packaging format and shipping conditions
If you want, you can share your target thickness and tolerance and I’ll calculate an estimated per-wafer mass range and translate it into a shipping-weight estimate per cassette/FOUP, which is often what operations teams really need.