Semiconductor Wafer Anchor Patterns for Defect Re-Location
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Solution Overview
Problem
Conventional defect inspection and review systems in semiconductor manufacturing face challenges in accurately aligning and re-locating defects due to large deviations between defect coordinates and inspection systems, leading to inefficiencies and reliance on user skill for manual defect finding.
Innovation Solution
A semiconductor structure with distinct anchor patterns and a method that involves identifying viewing fields, recognizing origin points, performing a first review step to correct offsets using these patterns, and a second review step to accurately locate defects, enabling automated offset correction and improved precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional defect inspection systems are used to detect defects on wafers, then defect locations can be identified, but large deviations occur between defect coordinates and inspection system alignment, reducing accuracy
Solution Approach 1:
The patent introduces mark patterns and anchor patterns as intermediary reference elements on the wafer. These patterns serve as mediators between the inspection system and review system, enabling accurate coordinate transformation and alignment. The mark patterns are detected by the inspection system, while anchor patterns are used by the review system, and their known spatial relationships allow precise defect re-location without direct system alignment.
2Measurement precision
If manual defect finding procedures are used to compensate for alignment deviations, then defect locations can be corrected, but time-consuming manual operations reduce productivity
Solution Approach 1:
The patent implements preliminary action by pre-forming mark patterns and anchor patterns on the wafer during manufacturing, and pre-calculating their spatial relationships. This allows the review system to automatically perform offset correction using these pre-prepared reference elements, eliminating the need for time-consuming manual defect finding and alignment procedures.
Solution Approach 2:
The review system performs self-service by automatically detecting mark patterns and anchor patterns, calculating coordinate transformations, and re-locating defects without human intervention. The system uses the known relationships between reference patterns to autonomously correct alignment deviations and complete the defect review process.
3Measurement precision
If alignment between inspection system and review system is performed, then defect coordinates can be transferred, but complex alignment procedures increase device complexity
Solution Approach 1:
The patent extracts the alignment function from the complex system-level alignment procedure and implements it through simple, pre-formed reference patterns on the wafer. Instead of aligning entire inspection and review systems, the solution extracts only the necessary reference elements (mark and anchor patterns) that enable coordinate transformation, significantly simplifying the alignment process.
Data Source
AI summary
A semiconductor structure includes a wafer comprising a plurality of viewing fields defined thereon, a plurality of dies defined by a scribe line formed in each viewing field, a plurality of mark patterns formed in the scribe line, and a plurality of anchor pattern respectively formed in the review fields, the anchor patterns being different from the mark patterns.