Exposure Apparatus Alignment Mark Shift for Reworked Substrates
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Solution Overview
Problem
In photolithography processes, reworked substrates with residual alignment marks from previous exposure processes can degrade detection accuracy, making it difficult to form accurate new alignment marks, which can lead to defects in device manufacturing.
Innovation Solution
An exposure apparatus that forms new alignment marks on reworked substrates at shifted positions to avoid overlapping with residual marks, ensuring accurate detection and positioning for subsequent exposure processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If alignment marks are formed on a substrate before resist film removal, then the substrate can be reused for subsequent exposure processes, but the residual marks from previous processes degrade the detection accuracy of new alignment marks
Solution Approach 1:
The patent extracts and removes the harmful residual alignment marks from the substrate surface through cleaning processes before forming new alignment marks. This eliminates the interference from previous process marks, restoring the substrate to a state suitable for accurate new mark formation and detection.
Solution Approach 2:
The patent performs preliminary cleaning of the substrate to remove residual alignment marks before forming new alignment marks. This preliminary action prevents the degradation of detection accuracy that would occur if new marks were formed directly over residual marks from previous processes.
2Ease of manufacture
If new alignment marks are formed at the same position as residual marks, then the marking process is simple, but the residual marks interfere with accurate detection of the new marks
Solution Approach 1:
The patent removes residual alignment marks through cleaning processes before forming new marks at the same position. This extraction of harmful residues allows simple co-location of marks without detection interference.
Solution Approach 2:
The patent applies preliminary cleaning actions to remove residual marks before new mark formation. This preliminary anti-action prevents the harmful effect of residual marks on detection accuracy, enabling simple mark formation at the same position.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach prevents degradation of detection accuracy and enables the successful reuse of reworked substrates by positioning new alignment marks outside the measuring range of residual marks, ensuring precise alignment and pattern formation.
Implementation Method 1
an exposure process to form a latent image by projecting a pattern onto a target position on the resist film on the substrate
Data Source
AI summary
The present invention provides an exposure apparatus including a forming unit configured to form a mark on a resist film on a substrate, and a control unit configured to perform an exposure process to form a latent image by projecting a pattern onto a target position on the resist film on the substrate based on a measured position of the mark, wherein the control unit causes the forming unit to perform a formation process of forming, before the exposure process is performed on a reworked substrate on which a second resist film has been formed after removing a first resist film with a first mark, a second mark on the second resist film so the second mark will be positioned at a position shifted from a position of the first mark on the reworked substrate.