Single Light Sensor for Dual Wafer Detection in End Effector
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Solution Overview
Problem
Existing end effectors in semiconductor manufacturing require multiple sensors for detecting wafer presence and mapping, leading to increased complexity and power consumption.
Innovation Solution
A dual optical sensor system is implemented within the end effector, utilizing a single light path with distinct segments for presence and mapping sensors, allowing a single light sensor to detect two conditions: wafer presence when loaded and wafer location when unloaded, reducing the number of sensors and components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If two separate sensors are used for presence and mapping detection, then detection accuracy is improved, but device complexity and power consumption increase
Solution Approach 1:
The single optical sensor is designed to perform multiple functions: presence detection and mapping detection. The sensor can detect different conditions (wafer presence on end effector vs. wafer location in storage) by receiving signals from different segments, eliminating the need for separate sensors while maintaining detection accuracy
Solution Approach 2:
The light path is divided into multiple segments (first segment for presence detection, second segment for mapping detection). Each segment corresponds to a specific detection function, allowing a single sensor to distinguish between different detection modes based on which segment is interrupted
2Adaptability or versatility
If two separate sensors with supporting electronics are placed in the end effector, then dual detection functions are achieved, but power consumption increases
Solution Approach 1:
A single optical sensor with supporting electronics performs both presence and mapping detection functions, reducing the total power consumption compared to running two separate sensors simultaneously. The sensor is activated based on the operational mode required
Solution Approach 2:
The sensor operates in different modes periodically or as needed - presence detection mode when wafer loading is required, and mapping detection mode when wafer location mapping is required. This periodic activation reduces overall power consumption compared to continuous operation of multiple sensors
3Adaptability or versatility
If additional sensors are built into the end effector for mapping, then wafer location mapping capability is improved, but the number of components increases
Solution Approach 1:
The same optical sensor used for presence detection is also used for mapping detection by detecting light path interruptions from different segments. This universal sensor approach provides both capabilities without increasing the sensor count
Solution Approach 2:
The presence detection and mapping detection functions are merged into a single sensor system. The light path is configured with multiple segments that can be detected by one sensor, combining what would traditionally require separate sensing systems into a unified approach
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
This solution simplifies the detection process, reduces sensor complexity and power consumption, while maintaining accurate wafer detection and mapping capabilities, enhancing the efficiency of wafer handling operations.
Implementation Method 1
the mapping sensor is defined by a first segment in the single light path such that the wafer intersects the first segment and interferes with the single light path
Implementation Method 2
the load sensor is defined by a second segment in the single light path such that the wafer intersects the second segment and interferes with the single light path
Data Source
AI summary
Systems, methods, and computer programs are presented for an end effector with a dual optical sensor. One end effector includes an arm, a mapping sensor, and a load sensor. The arm has one end connected to a pivoting joint, and a light signal is routed around the arm through a single light path. The mapping sensor is used for identifying the presence of the wafer when the wafer is not loaded on the end effector. The load sensor is used for identifying presence of the wafer on the end effector when the wafer is loaded on the end effector. The load sensor is defined by a second segment in the single light path such that the wafer intersects the second segment and interferes with the single light path when the wafer is loaded. A control module determines if an interruption in the single light path corresponds to an interruption of the single light path in the mapping sensor or the load sensor. As a result, one single light sensor is used to sense for two different conditions in the end effector.