Wafer Aligner Light-Absorbing Detection Space for Notch Accuracy
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Solution Overview
Problem
Existing wafer alignment methods are prone to misjudgments due to interference from external ambient light sources, affecting the accuracy of notch detection on semiconductor wafers.
Innovation Solution
A wafer aligner with a detection space formed by a light-absorbing surface and a detection structure that blocks external ambient light, allowing the light beam to pass through an opening and be received by an image capture device for precise notch detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a sensor is used to sense images of the wafer edge, then the alignment detection can be performed, but the sensor is affected by external ambient light source causing misjudgments
Solution Approach 1:
The patent converts the harmful effect of ambient light into a beneficial shielding mechanism by using light-absorbing surfaces. These surfaces are strategically positioned to block external light paths to the sensor while allowing the controlled light source to illuminate the wafer edge, thus transforming the light interference problem into an effective light management solution
Solution Approach 2:
The patent applies light-absorbing surfaces with specific optical properties to particular regions (the detection space boundaries) rather than uniformly across the entire device. This localized application of special material properties creates optimal detection conditions precisely where needed while maintaining other functional areas unchanged
2Reliability
If a light source illuminates the wafer edge for sensor detection, then the edge images can be captured, but external ambient light causes interference and misjudgments
Solution Approach 1:
The patent transforms the problematic ambient light environment into a controlled detection setup by introducing light-absorbing surfaces that selectively block external light. These surfaces create a controlled optical environment where only the intended light source reaches the sensor, converting the unreliable ambient condition into a reliable controlled illumination scenario
Solution Approach 2:
The light-absorbing surfaces act as intermediary elements between the external environment and the sensor. They mediate the light paths by absorbing unwanted ambient light while allowing the controlled light source to pass through, thus protecting the sensor from interference without blocking the necessary detection light
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 by preventing external light interference, enabling smooth image capture and precise alignment of the wafer notch for subsequent processing.
Implementation Method 1
at least one surface of the detection space formed by the stand and the body is a light-absorbing surface
Implementation Method 2
The control module drives the light source to project a light beam. The light beam sequentially passes through the body and the detection space
Data Source
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AI summary
A wafer aligner (100) that includes a body (110), a stage (130), a stand (120), an optical module (140) and a control module (CM) is provided. The stage (130) is movably disposed on the body (110). The stand (120) is vertically disposed on the body (110) and partially suspended above the body (110) to allow the stand (120) and the body (110) to form a detection space (IS). A wafer (200) is carried on the stage (130) and driven by the stage (130) to rotate relative to the body (110), and an edge of the wafer (200) passes by the detection space (IS). At least one surface of the detection space (IS) formed by the stand (120) and the body (110) is a light-absorbing surface. The optical module (140) includes a light source (142) and an image capture device (141).