Analysis of Overlay Errors in a 4-inch Si Wafer

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) at the top, bottom, left, right edges, and center of a 4-inch Si wafer are as follows: Top (T): 0.0 µm Right (R): 0.7 µm Center (C): 0.5 µm Left (L): 0.3 µm Bottom (B): 1.0 µm X-axis: 0.7 µm Y-axis: 1.0 µm

Types of Misalignments:

Overlay Errors Representation: The ϑ (overlay errors) in the 4-inch Si wafer represent various types of misalignments, including in/out error, rotational misalignment, and translational misalignment.

In/Out Error:

Definition: In/out error refers to the change in position of the overlay along the y-axis. It indicates the discrepancy in alignment between different points on the wafer. Example: For instance, the point at the bottom edge of the wafer experiences an in/out error of 0.3 µm.

Rotational Misalignment:

Definition: Rotational misalignment is determined by observing any changes in the orientation of the overlay. It indicates the angular misalignment between different points. Observation: By taking the center point as the reference, the left and right edges of the wafer show a slight rotational misalignment based on the recorded errors.

Translational Misalignment:

Definition: Translational misalignment refers to a uniform shift in position across all points on the wafer. It signifies the positional discrepancy of the overlay. Observation: There is a noticeable translational misalignment across all edges and the center of the wafer, indicated by the uniform positional shift. Conclusion: The quantification of in/out, rotational, and translational misalignments is crucial for ensuring the accuracy and reliability of the semiconductor manufacturing process.
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