LithographyMVP
Overlay error budget
Combine independent overlay contributions in quadrature to see a total overlay error.
Inputs
Result
Enter values and calculate to see the result.
Interpretation
Enter the X, Y, and process contributions (all as lengths).
Formula
total = √(X² + Y² + P²)
Independent contributions combine in quadrature.
Variables
| Symbol | Variable | Unit |
|---|---|---|
| total | Combined overlay error | m (shown as nm) |
| X | X-direction error | m |
| Y | Y-direction error | m |
| P | Process/distortion contribution | m |
Assumptions & validity
This tool assumes:
- Contributions are independent and combine in quadrature (RSS).
- Educational model — not a specific fab's overlay budget.
- Correlated/systematic errors are not captured by this combination.
Worked example
X = 3 nm, Y = 4 nm, P = 0.
total = √(3² + 4² + 0²) = 5 nm