Wafer Edge Gap Detection for Fast Substrate 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 measure the gap between the wafer and a datum structure, such as an edge ring or chuck, to adjust the wafer's position accurately without requiring blanket wafers, providing real-time feedback for robotic arm calibration.
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 cost and time consumption increase significantly
Solution Approach 1:
The patent uses camera images to create a visual copy or representation of the wafer position relative to the edge ring, replacing the need for physical blanket wafers. The camera captures the gap between the wafer and edge ring, providing measurement data without consuming additional wafer materials.
Solution Approach 2:
The patent replaces the mechanical/physical blanket wafer method with an optical measurement system using cameras. Instead of using physical blanket wafers for etch rate and particle data, the system uses optical imaging to directly measure wafer position and calculate centering accuracy.
2Measurement precision
If blanket wafers are used for etch rate and backside particle data, then wafer centering accuracy is improved, but cost increases due to expensive blanket wafers
Solution Approach 1:
The patent uses camera images to create a visual copy or representation of the wafer position relative to the edge ring, replacing the need for physical blanket wafers. The camera captures the gap between the wafer and edge ring, providing measurement data without consuming additional wafer materials.
Solution Approach 2:
The patent replaces expensive blanket wafers with a reusable camera system. The camera can be used repeatedly to measure wafer position for multiple wafers, eliminating the need to consume costly blanket wafers for each centering measurement.
3Manufacturing precision
If multiple cameras are used to measure gap size, then positioning accuracy is improved, but device complexity increases
Solution Approach 1:
The patent divides the measurement task among multiple cameras, with each camera measuring the gap at a specific location. This segmentation allows for more comprehensive coverage and higher positioning accuracy while keeping each individual camera simple and manageable.
Solution Approach 2:
The patent uses multiple cameras that can serve different functions - some cameras may measure gap at different locations, or the same camera may be used for different wafers. This multi-functionality improves positioning accuracy while justifying the added complexity through versatile utility.
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.