Semiconductor Defect Inspection Using Polarized Photoluminescence
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Solution Overview
Problem
Current semiconductor defect inspection technologies face challenges in effectively detecting dislocation defects on patterned surface layers of semiconductor substrates, particularly in distinguishing between surface and subsurface defects.
Innovation Solution
A semiconductor defect inspection apparatus utilizing obliquely incident excitation light, converted to s-polarized or p-polarized light, to generate photoluminescence images, allowing for the detection and classification of dislocation defects by analyzing the penetration depth and intensity differences between s-polarized and p-polarized light images.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If obliquely incident excitation light is used to generate photoluminescence images, then defect detection accuracy is improved, but device complexity increases due to polarization converters and multiple detectors
Solution Approach 1:
The patent divides the detection function into multiple specialized detectors: a first detector for s-polarized photoluminescence light and a second detector for p-polarized photoluminescence light. This segmentation allows each detector to specialize in detecting specific polarization components, improving measurement precision while maintaining manageable device complexity through functional decomposition
Solution Approach 2:
The patent introduces polarization converters as intermediary components that transform the excitation light into specific polarization states (s-polarized or p-polarized). These intermediaries enable precise control over the excitation light's polarization, which is essential for achieving high defect detection accuracy through photoluminescence imaging
2Measurement precision
If s-polarized light is used for excitation, then surface layer defect detection is enhanced, but subsurface defect detection capability is reduced
Solution Approach 1:
The patent employs dynamic switching between different polarization states of excitation light. By alternately using s-polarized light (for surface layer detection) and p-polarized light (for subsurface detection), the system adapts its detection capability to different defect depths, preventing information loss while maintaining high surface detection precision
Solution Approach 2:
The patent changes the polarization parameter of the excitation light to access different detection depths. By switching between s-polarization and p-polarization states, the system modifies the penetration characteristics of the excitation light, enabling selective detection of surface versus subsurface defects without permanent loss of detection capability
3Measurement precision
If p-polarized light is used for excitation, then subsurface defect detection is enhanced, but surface layer defect detection capability is reduced
Solution Approach 1:
The system dynamically switches between p-polarized and s-polarized excitation light modes. When p-polarized light is used for enhanced subsurface detection, the system compensates for reduced surface detection capability by subsequently using s-polarized light, ensuring no surface defect information is permanently lost
Solution Approach 2:
The patent implements periodic alternation between different polarization excitation modes. The excitation light periodically switches between s-polarization and p-polarization states, allowing the system to repeatedly access both surface and subsurface defect information, preventing information loss through comprehensive periodic sampling
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 selective detection of dislocation defects on the surface layer, improving defect detection accuracy and efficiency in semiconductor manufacturing processes by distinguishing between surface and subsurface defects.
Implementation Method 1
A semiconductor defect inspection apparatus utilizing obliquely incident excitation light, converted to s-polarized or p-polarized light, to generate photoluminescence images
Implementation Method 2
converted to s-polarized or p-polarized light
Data Source
AI summary
A semiconductor defect inspection apparatus for inspecting a specimen including a semiconductor substrate having a surface on which a predetermined pattern is formed, includes an excitation light irradiator, a polarization converter, a detector, and a defect analysis detector. The excitation light irradiator irradiates the specimen with excitation light along an optical path from the irradiator to the specimen and such that the excitation light is obliquely incident at a predetermined incident angle. The first polarization converter is disposed in the optical path, and converts the excitation light into s-polarized light. The detector detects photoluminescence light generated from the specimen when the excitation light is incident on the specimen. The defect analysis detector detects a dislocation defect by analyzing a photoluminescence image obtained by photoelectrically converting the photoluminescence light.