1. Vector Raptor Overlay Analysis for High-Density ASML Data
Vector Raptor measured Modeled Rotation showing Full-Field and slit rotation in fields (upper plot)
BCD data from scatter Tool (bottom)
Vector Raptor Overlay Analysis for High-Density ASML Data
ASML measured overlay data
14,900+ data points
June 12, 2007

2. Vector Raptor Advanced Overlay Analysis & Modeling
ASML Scanner measured data
Model raw data for each structure separately
Remove outliers by using the model’s ability for variable-based culling
Apply a simple wafer model
Remove wafer-model errors
Examine IntraField overlay variation error sources

3. ASML Data file
14,918 overlay data points after 20 data points are removed using the X-Reg variable for culling

4. Raw vectored data and sites on field
Field-Site Layout
Total of 14,918 sites
20 sites excluded by culling (> 10 nm error)
Raw Overlay Data

5. X & Y overlay – Contour Plots of raw data
Xreg data
Yreg data
Y-reg alignment error
Fine-structure rib variation of 3-5 nm due to reticle-scan
Process error in both X & Y

6. Wafer Model, magnitude variation
Y-reg alignment error

7. Wafer-modeled X overlay
Full-wafer modeled variation of X-overlay due to process and setup errors.

8. Residuals to wafer model, X-overlay
Xreg Variation along a field vertical axis
Note cycle every 4 mm on scan
Wafer-modeled errors removed
IntraField variation
Note graph above showing X-overlay as a function of row-position on field
4 mm cycle due to reticle-stage travel.
Approximately 1.5 nm of error
Yreg error is greater

9. Residuals to wafer model, X-overlay
5 mm scan-period
Row location on field

10. X & Y Vector residuals to wafer registration
Vector plot , Same data as previous slide

11. Variation across wafer diameter
Xreg data
Yreg data
Residuals to wafer model
Plotted X & Y overlay across center row of wafer
Note greater variation of Yreg data