External Optical Wafer Position Detection in Transfer Robot Vacuum Chambers
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Solution Overview
Problem
In multi-chamber wafer systems, existing technologies face challenges in accurately monitoring the location of wafers within the transfer robot vacuum chamber (TRVC) during transfer, which affects alignment and processing efficiency.
Innovation Solution
A location detection system comprising illumination units and sensing units outside the TRVC, utilizing TRVS reflecting elements to direct and reflect radiation patterns, allowing for accurate wafer location determination through changes in radiation patterns, and a location processing circuit to interpret these signals for precise wafer positioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a location detection system is implemented within the TRVC to monitor wafer position, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent introduces reflecting elements as intermediary components that facilitate optical interaction between the external illumination/sensing units and the wafer. These reflecting elements enable the detection system to function without requiring direct line-of-sight access to the wafer from within the vacuum chamber, thereby achieving precise location measurement while maintaining system simplicity through external component placement
Solution Approach 2:
The patent replaces potential mechanical contact-based detection methods with an optical detection system consisting of illumination units, sensing units, and reflecting elements. This substitution eliminates mechanical complexity while achieving high measurement precision through non-contact optical sensing of wafer position
2Measurement precision
If detection components are placed inside the TRVC to directly monitor the wafer, then measurement precision is improved, but contamination risk increases
Solution Approach 1:
The reflecting elements serve as intermediaries that enable optical sensing without requiring physical detection components inside the vacuum chamber. The illumination and sensing units remain outside the TRVC, using the reflecting elements to indirectively measure wafer position, thus achieving precise detection while eliminating contamination risk from internal components
Solution Approach 2:
The patent extracts the illumination and sensing units from the vacuum chamber environment and places them externally. By taking out the potential contamination sources (detection components) from the sensitive vacuum environment, the system maintains measurement precision through optical coupling while eliminating the harmful contamination effect
3Manufacturing precision
If traditional internal detection methods are used, then alignment accuracy is improved, but maintenance costs and complexity increase
Solution Approach 1:
The reflecting elements act as simple, passive intermediaries that can be easily replaced or adjusted without affecting the complex illumination and sensing units. This configuration enables high alignment accuracy while reducing maintenance complexity, as the passive reflecting elements have no moving parts or power requirements inside the vacuum chamber
Solution Approach 2:
The patent replaces mechanical alignment detection systems with an optical system where the wafer's position is detected through optical interactions with reflecting elements. This substitution reduces maintenance requirements by eliminating mechanical wear components while maintaining high alignment precision through optical measurement
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
Enables accurate and efficient wafer location detection within the TRVC, reducing contamination, maintenance costs, and improving alignment processes, while being easily integratable with existing systems.
Implementation Method 1
TRVS reflecting elements to direct and reflect radiation patterns
Data Source
AI summary
A location detection system for detecting a location of a wafer within a transfer robot vacuum chamber (TRVC), the detection system may include (i) an illumination unit that is configured to direct a transmitted radiation pattern through a transparent window of the TRVC and towards one or more TRVS reflecting elements located below an upper side of a wafer holding element of the transfer robot; wherein the illumination unit is located outside the TRVC; (ii) a sensing unit that is configured to generate one or more detection signals indicative of a received radiation pattern that is reflected from the one or more TRVS reflecting elements; and (iii) a location processing circuit that is configured to detect a location of the wafer based on the one or more detection signals.