Second Harmonic Generation Semiconductor Measurement Device
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Solution Overview
Problem
Traditional physical measurement devices are inadequate for precise, high-throughput evaluations of physical properties in semiconductor manufacturing, such as impurity distribution, stress analysis, and defect detection, due to limitations in non-destructive, contactless, and high-resolution measurements.
Innovation Solution
A second harmonic generation (SHG) measurement device utilizing a femtosecond pulsed laser, nonlinear optical crystal, birefringent crystal, and image detector to convert and analyze the fundamental and second harmonics, enabling non-contact, high-resolution measurements of surface and internal properties of semiconductor devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional physical measurement devices (OCD systems, CD-SEMs) are used, then device complexity is reduced, but measurement precision and capability are insufficient for evaluating physical properties like impurity distribution, stress, and defect detection
Solution Approach 1:
The patent introduces a nonlinear optical crystal as an intermediary element that converts fundamental laser waves into second harmonic waves through second harmonic generation. This intermediary process enables precise measurement of physical properties by creating wavelength-specific signals that interact with the measurement object, thereby achieving high measurement precision without requiring direct complex interaction between the measurement device and the object's physical properties
Solution Approach 2:
The patent replaces traditional mechanical and electrical measurement systems with an optical-based measurement system using laser beams, nonlinear optical crystals, and image detectors. This substitution eliminates the need for physical contact and complex electrical probing, achieving non-destructive, high-precision measurement of physical properties through optical field interactions
2Measurement precision
If chemical methods (fluorescent X-rays, mass spectrometry) are used, then measurement precision is improved, but productivity decreases due to destructive nature and inability to perform high-throughput measurements
Solution Approach 1:
The measurement system uses the measurement object itself (semiconductor wafer) to generate the measurement signal through second harmonic generation. The object's physical properties directly modulate the optical signal without requiring external chemical reagents or destructive sampling, enabling non-destructive, high-throughput measurement that maintains both precision and productivity
Solution Approach 2:
The patent replaces destructive chemical analysis methods with non-destructive optical measurement using second harmonic generation. This substitution allows rapid, high-throughput measurement without consuming or damaging the measurement object, thereby maintaining high productivity while achieving precise detection of impurities and physical properties
3Measurement precision
If electrical characteristic evaluations (C-V characteristics, OBIRCH, LADA) are used, then measurement precision for specific defects is improved, but adaptability decreases due to contact-based measurements limited to post-processing stages
Solution Approach 1:
The patent replaces contact-based electrical measurement methods with non-contact optical measurement using second harmonic generation. This substitution removes the limitation of requiring physical contact and wiring, enabling measurement across all processing stages from early fabrication to final inspection, thereby achieving both high defect detection precision and universal adaptability
Solution Approach 2:
The measurement system is designed to measure multiple physical properties (impurity distribution, stress, crystal orientation, defect detection) using a single optical-based platform. The system can operate at various processing stages without requiring different measurement techniques, achieving universal adaptability while maintaining precision through the versatile second harmonic generation methodology
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 SHG measurement device achieves significant improvements in measurement precision and throughput, allowing for rapid detection of surface contamination, internal dopant amounts, and other critical semiconductor properties, thereby enhancing manufacturing yields and process feedback.
Implementation Method 1
a second harmonic generator configured to convert a portion of the fundamental wave into a first-second harmonic
Implementation Method 2
a birefringent crystal configured to split an angle for the first-second harmonic
Implementation Method 3
a polarizer configured to polarize the first-second harmonic and the second-second harmonic to approximately same polarizations
Implementation Method 4
an image detector configured to convert the first-second harmonic and the second-second harmonic, which are incident at different angles from each other, into an electrical signal
Data Source
AI summary
A measurement device includes a light source configured to emit a fundamental wave that is a femtosecond pulsed laser beam, a second harmonic generator configured to convert a portion of the fundamental wave into a first-second harmonic, a birefringent crystal configured to split an angle for the first-second harmonic, a wavelength selection element configured to block the fundamental wave and transmit therethrough the first-second harmonic and a second-second harmonic, a polarizer configured to polarize the first-second harmonic and the second-second harmonic to approximately same polarizations, and an image detector.