Semiconductor Wafer Evaluation Using Multi-Angle Polarized Laser Detection
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Solution Overview
Problem
Current methods for evaluating semiconductor wafers with polished surfaces are inadequate in detecting process-induced defects and surface-adhered foreign matters, as they rely on single light point defect detection techniques that fail to differentiate between these abnormalities effectively.
Innovation Solution
A novel evaluation method using a laser surface-inspection device with one incident system and three light-receiving systems, where at least one system differs in light-receiving angle and polarization selectivity, allows for the detection of abnormalities by analyzing radiation light reflected or scattered from the polished surface, enabling discrimination between process-induced defects and surface-adhered foreign matters based on measurement results from different light-receiving systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single light point defect detection technique is used, then the evaluation process is simple, but the detection sensitivity and accuracy for process-induced defects and surface-adhered foreign matters is insufficient
Solution Approach 1:
The evaluation system is segmented into multiple light-receiving systems (first, second, and third light-receiving systems), each configured to detect light from different directions or with different polarization characteristics. This segmentation allows simultaneous detection of multiple types of abnormalities with high accuracy while maintaining a systematic and organized evaluation approach.
Solution Approach 2:
The invention introduces additional detection dimensions by configuring light-receiving systems to receive light at different angles (e.g., different incident angles or azimuth angles) and/or with different polarization selectivities. This multi-dimensional detection approach enables differentiation between process-induced defects and surface-adhered foreign matters, significantly improving detection accuracy without creating a chaotic system.
2Reliability
If multiple light-receiving systems with different configurations are used, then the ability to differentiate between process-induced defects and surface-adhered foreign matters is improved, but the device complexity increases
Solution Approach 1:
The multiple light-receiving systems are designed with different configurations (different incident angles, azimuth angles, or polarization selectivities) to perform multiple detection functions simultaneously. Each system contributes to a comprehensive evaluation, enabling reliable differentiation between process-induced defects and surface-adhered foreign matters through their combined multi-functional capabilities.
Solution Approach 2:
The invention changes key optical parameters of the light-receiving systems, specifically the incident angles, azimuth angles, and/or polarization selectivities. By systematically varying these parameters across different light-receiving systems, the evaluation reliability is enhanced as each system detects different characteristics of abnormalities, allowing for robust differentiation while maintaining a structured system architecture.
3Measurement precision
If conventional single-system detection is used, then the device structure is simple, but the detection sensitivity for both process-induced defects and surface-adhered foreign matters is inadequate
Solution Approach 1:
The inspection device is segmented into multiple specialized light-receiving systems, each optimized for detecting specific types of abnormalities. This segmentation enhances detection sensitivity for both process-induced defects and surface-adhered foreign matters by assigning different detection configurations to different abnormality types, while maintaining a systematic device structure.
Solution Approach 2:
The invention adds detection dimensions by configuring light-receiving systems with different incident angles, azimuth angles, and/or polarization selectivities. This multi-dimensional detection capability significantly improves detection sensitivity for various abnormality types, transforming a single-dimension detection system into a comprehensive multi-dimensional evaluation system.
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 method enhances the detection sensitivity and accuracy for both process-induced defects and surface-adhered foreign matters, allowing for effective process control and quality assurance in semiconductor wafer manufacturing by distinguishing between these abnormalities.
Implementation Method 1
receiving, with a first light-receiving system, radiation light which has been radiated by the incident light being reflected or scattered by the polished surface
Implementation Method 2
receiving, with a first light-receiving system, radiation light which has been radiated by the incident light being reflected or scattered by the polished surface
Implementation Method 3
at least one selected from the group consisting of a light-receiving angle and polarization selectivity differs among the first light-receiving system, the second light-receiving system, and the third light-receiving system
Data Source
AI summary
A method of evaluating a semiconductor wafer, which has a polished surface, by using a laser surface-inspection device including light-incident and light-receiving systems, includes evaluating the semiconductor wafer by detecting, as a light point defect, an abnormality of a process-induced defect and a surface-adhered foreign matter present on the polished surface of the semiconductor wafer, on the basis of measurement result obtained by directing incident light to the polished surface of the semiconductor wafer from one light-incident system and receiving, with a first light-receiving system, radiation light which has been radiated by the incident light being reflected or scattered by the polished surface, measurement result obtained by receiving the radiation light with a second light-receiving system, and measurement result obtained by receiving the radiation light with a third light-receiving system, and at least one of a light-receiving angle and polarization selectivity differs among the first, second and third light-receiving systems.