Laser Light Scattering for Wafer Alignment and Surface Verification
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Solution Overview
Problem
Existing semiconductor processing systems face challenges in accurately determining the alignment, cleanliness, and surface quality of semiconductor wafers, particularly due to misalignment issues during handling and processing.
Innovation Solution
A system utilizing a coherent light source, such as a laser, to emit a light beam onto the semiconductor wafer, scattering the light to create a diffraction and speckle pattern. This pattern is then analyzed to determine the orientation, cleanliness, and surface quality of the wafer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a light presence sensor is used to determine workpiece orientation, then the alignment can be verified, but misalignment issues persist during handling and processing
Solution Approach 1:
The patent replaces traditional mechanical alignment verification methods with laser light scattering technology. The laser beam scatters off the workpiece surface, and the scattering pattern is analyzed to determine orientation and alignment with high precision, eliminating reliance on mechanical sensors that are prone to misalignment during handling.
Solution Approach 2:
The patent changes the measurement parameter from simple light presence detection to analysis of light scattering patterns. By analyzing the angular distribution and intensity of scattered light, the system achieves more reliable and precise alignment verification that is insensitive to handling variations.
2Device complexity
If traditional alignment methods are used, then the process is simple, but alignment accuracy and surface quality verification are insufficient
Solution Approach 1:
The laser light scattering system performs multiple functions simultaneously: it verifies workpiece orientation, detects alignment accuracy, and assesses surface quality all through a single measurement approach. This multi-functional capability achieves high manufacturing precision without proportionally increasing device complexity.
Solution Approach 2:
The patent replaces complex mechanical alignment systems with an optical-based laser scattering system that provides both simplicity and high precision. The optical method eliminates the need for multiple mechanical components while delivering superior measurement accuracy for alignment and surface characteristics.
3Adaptability or versatility
If multiple separate verification methods are used for alignment and surface quality, then comprehensive verification is achieved, but system complexity increases
Solution Approach 1:
The laser light scattering system is designed to perform multiple verification tasks through a unified approach. The same scattered light pattern analysis provides information about workpiece orientation, alignment status, and surface quality, eliminating the need for separate verification systems and reducing overall complexity.
Solution Approach 2:
The patent merges alignment verification and surface quality assessment into a single integrated measurement process. By combining these functions into one laser-based system, the patent achieves comprehensive verification capability while minimizing system complexity through functional integration.
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
The system effectively minimizes alignment errors and provides accurate verification of wafer characteristics, enhancing the precision and efficiency of semiconductor processing.
Implementation Method 1
emit a coherent light beam onto the workpiece surface and to scatter the coherent light beam from the workpiece surface to define a scattered light beam distribution
Implementation Method 2
the scattered light beam distribution comprises a diffraction pattern having one or more maxima arranged along a first axis
Data Source
AI summary
A system and method are provided for determining one or more characteristics of a workpiece based on a scattered light beam distribution. An emission apparatus emits a coherent light beam on a surface of the workpiece and the coherent light beam may scatter upon interacting with the surface, defining the scattered light beam distribution. The scattered light beam distribution may be based on one or more attributes of the surface of the workpiece where one or more characteristics of the workpiece are determined based on the scattered light beam distribution. A receiver apparatus images the scattered light beam distribution, and a controller is configured to determine one or more characteristics of the workpiece based on the image data.