Semiconductor Overlay Pattern Layout for Precise Layer Alignment
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Solution Overview
Problem
As semiconductor devices become increasingly complex and multi-layered, overlay control in semiconductor fabrication processes faces challenges due to misalignment issues between layers, leading to potential connection failures and short circuits, where current methods using regular overlay patterns are insufficient for accurate alignment verification.
Innovation Solution
A semiconductor pattern comprising irregularly arranged first and second unit images, with the second unit images equidistantly spaced, forming an outer part and an inner part, is used to generate an overlay error dataset, which informs adjustments to process parameters for improved alignment in subsequent manufacturing batches.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If regular overlay patterns are used for alignment verification, then the measurement process is simple, but the measurement precision is insufficient for complex multi-layer semiconductor devices
Solution Approach 1:
The overlay pattern is segmented into multiple distinct regions: a first region with first unit images arranged in a first arrangement pattern, and a second region with second unit images arranged in a second arrangement pattern. This segmentation allows each region to serve specific measurement functions, improving overall measurement precision while maintaining manageable complexity through structured organization.
Solution Approach 2:
Different regions of the overlay pattern are designed with different local qualities - the first region uses a first arrangement pattern suitable for certain measurement aspects, while the second region uses a second arrangement pattern for other measurement aspects. This local differentiation enables accurate measurement of various alignment parameters across different areas of the semiconductor device.
2Reliability
If overlay patterns are defined on multiple layers to detect misalignment, then the alignment control capability is improved, but the process complexity and time consumption increase
Solution Approach 1:
The overlay pattern is pre-defined with multiple regions and arrangement patterns before the semiconductor fabrication process begins. This preliminary design enables rapid measurement and detection of overlay errors during manufacturing, reducing the time required for alignment verification and compensation adjustments.
Solution Approach 2:
The overlay pattern structure serves multiple functions simultaneously: it can measure alignment accuracy in different directions, verify overlay errors across multiple layers, and provide reference data for compensation calculations. This multi-functionality reduces the need for multiple separate measurement processes, saving time while maintaining reliable alignment control.
Data Source
AI summary
A semiconductor pattern includes a first pattern section and a second pattern section. Each of the first pattern section and the second pattern section includes a plurality of irregularly arranged first unit images and at least one set of second unit images disposed outside the first unit images. Each set of second unit images includes a plurality of second unit images that are equidistantly spaced apart from one another. The sets of second unit images of the first pattern section and the second pattern section form an outer part. The outer part has a plurality of sides, and each side is formed by one set of second unit images of the first pattern section and a corresponding set of second unit images of the second pattern section.