What are the observed errors in x and y (in µm) at the top, bottom, left, right edges, and center of a 4-inch Si wafer?
The observed errors in x and y (in µm) for the 4-inch Si wafer are as follows:
- Top (T): x=0.0 µm, y=0.7 µm
- Right (R): x=0.7 µm, y=1.0 µm
- Center (C): x=0.5 µm, y=0.5 µm
- Left (L): x=0.3 µm, y=0.0 µm
- Bottom (B): x=1.0 µm, y=0.3 µm
Analysis of Overlay Error
Final Answer: The analysis of the overlay error in a silicon wafer involves looking at the in/out, rotational, and translational misalignment. While the in/out misalignment seems to be slightly present based on the provided data, the rotational misalignment is hard to determine without errors at diagonal points. The translational misalignment is not evident in the provided data.
Explanation:
To analyze the overlay error, you need to consider the in/out, rotational, and translational misalignment. To assess in/out misalignment, you look at errors at the top and bottom of the wafer (Y-direction) and the left and right (X-direction). Your data suggests there might be slight in/out misalignment since the errors are not the same in all directions.
Rotational misalignment can be assessed by comparing the errors at diagonally opposite points of the wafer. If there is a significant difference, it indicates a rotational error. Your data does not provide errors for diagonal points, so it's difficult to thoroughly analyze rotational misalignment.
Lastly, for translational misalignment, check whether there is a consistent error in one particular direction. If there is, it would lead to a shift in the entire wafer's features. In your data, such consistent directional error is not evident.