Single-Image Alignment Mark Detection for Dense Die Substrates
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Solution Overview
Problem
Existing lithography and metrology tools require multiple images to identify and locate alignment marks on densely packed integrated circuits, leading to reduced productivity and increased production time.
Innovation Solution
A system and method to identify and locate multiple alignment marks within a single image, utilizing a digital lithography system with a camera and alignment mark identification system to determine the positions of alignment marks on a substrate, reducing the number of processing resources and time required.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple images are used to identify and locate alignment marks on densely packed integrated circuits, then measurement precision is improved, but productivity deteriorates due to reduced output per unit time
Solution Approach 1:
The patent combines multiple alignment mark detections into a single image capture operation. The camera system is configured to capture multiple dies simultaneously, and the processing system identifies and locates multiple alignment marks within that single image, merging what would traditionally require multiple separate imaging operations into one unified operation, thereby maintaining precision while improving throughput
Solution Approach 2:
The patent transitions from sequential processing (one alignment mark at a time across multiple images) to parallel processing by utilizing the spatial dimension of a single wide-field image. By capturing multiple alignment marks across different dies in one image frame and processing them simultaneously, the system adds a spatial parallelism dimension that resolves the contradiction between precision and productivity
2Measurement precision
If multiple images are captured to locate alignment marks, then detection accuracy is improved, but loss of time increases due to multiple processing operations
Solution Approach 1:
The patent implements continuous useful action by processing multiple alignment marks within a single uninterrupted image capture and processing cycle. Instead of capturing, processing, and moving to the next image sequentially, the system performs continuous detection and location operations on multiple alignment marks simultaneously within one image, eliminating idle time between operations and maintaining continuous productive action
Solution Approach 2:
The patent applies preliminary action by capturing all necessary alignment mark data in a single image before any processing begins. The entire set of alignment marks across multiple dies is captured in advance in one operation, and then all location calculations are performed simultaneously from that pre-captured data, eliminating the need for repeated capture and processing cycles
Data Source
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AI summary
A system includes a memory and at least one processing device, operatively coupled to the memory, to detect, in an image of a plurality of dies on a substrate, a plurality of alignment marks, wherein each die of the plurality of dies includes at least one alignment mark of the plurality of alignment marks, select an alignment mark from the plurality of alignment marks, determine an identity of the alignment mark, and determine a location of the alignment mark.