Optical Substrate Detection for Tilted and Multi-Stacked Wafers
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Solution Overview
Problem
Existing substrate handling systems lack precision and consistency in detecting misaligned substrates, leading to potential damage and contamination due to imprecise alignment methods and tools that rely on subjective visual inspections or contact, resulting in breakage and particulate generation.
Innovation Solution
Implementing a system with dual emitters and detectors, such as laser beams and light sensors, positioned at opposing angles to accurately detect and differentiate between single and multi-stacked substrates, as well as tilted substrates, using software to analyze signals and distinguish between these conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If contact-based alignment tools are used to assist operator alignment, then alignment precision may be improved, but the risk of wafer breakage, scratching, and particulate generation increases
Solution Approach 1:
The patent replaces contact-based mechanical alignment tools with a non-contact optical detection system. The system uses optical sensors and image processing to detect substrate position and provide alignment guidance, eliminating physical contact between tools and substrates while maintaining high alignment precision.
Solution Approach 2:
The patent introduces an optical field as an intermediary between the operator and the substrate. Instead of direct mechanical contact, the system uses light to detect substrate position and provide alignment information, serving as a harmless mediator that transfers information without causing damage.
2Device complexity
If subjective visual inspection is used for substrate alignment, then the system complexity remains low, but measurement precision and consistency deteriorate
Solution Approach 1:
The patent replaces subjective human visual inspection with an automated optical detection system. The system uses optical sensors, cameras, and image processing algorithms to objectively measure substrate position, providing consistent and precise measurements without the variability inherent in human vision.
Solution Approach 2:
The patent creates an optical copy or image of the substrate position using cameras and optical sensors. This digital representation allows for precise measurement and analysis without physically touching the substrate, enabling automated detection and alignment guidance.
3Productivity
If imprecise alignment methods are used, then the handling speed may be maintained, but substrate breakage and equipment damage increase
Solution Approach 1:
The patent performs preliminary detection and alignment guidance before the actual substrate handling operation. The optical detection system identifies position errors early, allowing the operator to make corrections before placement, thus preventing damage while maintaining efficient handling flow.
Solution Approach 2:
The patent implements a feedback mechanism where the optical detection system continuously monitors substrate position and provides real-time alignment guidance. This feedback loop allows for dynamic adjustment of placement position, ensuring high precision while maintaining efficient handling speed.
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
Enhances detection accuracy, reducing substrate damage and contamination by precisely identifying misplacements, distinguishing between tilted and multi-stacked substrates, and improving substrate handling efficiency.
Implementation Method 1
a first beam positioned within the material handling system, the first beam is in optical communication with the top surface of the substrate; a second beam positioned within the material handling system, the second beam is in optical communication with the bottom surface of the substrate
Data Source
AI summary
A method for distinguishing between tilted and multi-stacked substrates in Automated Material-Handling Systems comprising the following steps. A substrate cassette having at least one substrate is provided. The substrate cassette is positioned within the material handling system. Each substrate has a top surface and a bottom surface. A first beam is emitted from a first emitter wherein the first beam is in optical communication with the top surface of the substrate. A second beam is emitted from a second emitter wherein the second beam is in optical communication with the bottom surface of the substrate. The first beam and the second beam are detected using at least one detector while vertically moving the substrate cassette relative to the first emitter or the second emitter.