Multi-Camera Wafer Positioning for Fast Datum-Based Centering
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Solution Overview
Problem
Existing wafer centering methods in semiconductor manufacturing are costly and cumbersome due to the use of blanket wafers for etch rate and backside particle data, which are expensive and time-consuming.
Innovation Solution
A system using camera arrangements with multiple cameras to capture images of the wafer and datum structure edges, determining gap sizes, and adjusting wafer position relative to the datum structure for precise centering, eliminating the need for blanket wafers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If blanket wafers are used for etch rate and backside particle data, then wafer centering accuracy is improved, but manufacturing cost increases and process time is extended
Solution Approach 1:
The patent uses camera images to create a visual copy of the wafer and datum structure edges, replacing the physical blanket wafer method. The processor analyzes these image copies to determine gap sizes and calculate wafer offset, achieving centering accuracy without consuming expensive blanket wafers or extending process time
Solution Approach 2:
The patent replaces the mechanical/physical blanket wafer-based measurement system with an optical imaging system. Cameras capture images and the processor electronically analyzes edge positions and gap sizes, substituting physical material consumption with light-based detection that is both faster and less costly
2Measurement precision
If blanket wafers are used for etch rate and backside particle data, then wafer centering accuracy is improved, but manufacturing cost increases
Solution Approach 1:
The patent uses camera images to create a visual copy of the wafer and datum structure edges, replacing the physical blanket wafer method. The processor analyzes these image copies to determine gap sizes and calculate wafer offset, achieving centering accuracy without consuming expensive blanket wafers
Solution Approach 2:
The patent replaces expensive blanket wafers with inexpensive camera images as the measurement medium. The images are captured, analyzed, and discarded after use, providing a cheap alternative to costly consumable wafers while maintaining measurement precision
3Measurement precision
If multiple cameras are used to capture wafer and datum structure edges, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent divides the measurement task among multiple cameras, with each camera capturing a specific field of view showing wafer edges and datum structures. The processor then integrates data from these segmented views to calculate comprehensive gap sizes and wafer offset, improving measurement precision through distributed observation
Solution Approach 2:
The patent makes each camera multi-functional by positioning them to capture both wafer peripheral edges and datum structure edges within their fields of view. This universal approach allows the same camera system to perform multiple measurement functions simultaneously, reducing overall system complexity
Data Source
AI summary
Systems and methods are provided for positioning a wafer in relation to a datum structure. In one example, a system comprises a camera arrangement including at least two cameras, each of the at least two cameras including a field of view when positioned in the camera arrangement, each field of view including a peripheral edge of the wafer and a peripheral edge of the datum structure. A processor receives positional data from each of the at least two cameras and determines, in relation to each field of view, a gap size between the respective peripheral edges of the wafer and the datum location included in the respective field of view. A controller adjusts a position of the wafer relative to the datum structure based on the determined respective gap sizes.