Non-contact Thin Film Defect Analysis via Laser Excitation
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Solution Overview
Problem
Current technologies lack a non-contact and non-destructive method for analyzing defects in thin films within semiconductor devices, which is crucial as semiconductor technology advances to ultra-fine patterns.
Innovation Solution
A process monitoring method and apparatus that injects a laser beam to form excited carriers in a thin film, irradiates an electromagnetic wave during carrier recombination, measures characteristic information such as transmittance or reflectance, and calculates carrier recombination time constants to determine defect types and densities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional contact-based or destructive methods are used for thin film defect analysis, then measurement capability is achieved, but the thin film is damaged or the measurement process is complex
Solution Approach 1:
The patent replaces mechanical contact-based measurement methods with optical field-based methods. A laser beam irradiates the thin film to generate excited carriers, and electromagnetic waves detect these carriers without physical contact, eliminating mechanical damage while maintaining measurement capability
Solution Approach 2:
The patent introduces excited carriers as an intermediary between the laser beam and the electromagnetic wave. The laser generates excited carriers in the thin film, and the electromagnetic wave detects these carriers through transmittance or reflectance changes, enabling indirect non-destructive measurement of thin film properties
2Reliability
If non-contact electromagnetic wave measurement is used without laser excitation, then the thin film remains undamaged, but excited carriers cannot be generated for defect analysis
Solution Approach 1:
The patent applies preliminary action by using a laser beam to pre-generate excited carriers in the thin film before electromagnetic wave measurement. This preliminary excitation creates detectable signals that reveal defect information without requiring contact during the actual measurement phase
Solution Approach 2:
The patent changes the physical state of carriers in the thin film by using laser excitation to create excited carriers with specific energy states. This parameter change (from ground state to excited state) enables the carriers to interact with electromagnetic waves in a detectable manner, providing defect information
3Measurement precision
If multiple defect types are analyzed separately, then comprehensive defect information is obtained, but the measurement process becomes time-consuming
Solution Approach 1:
The patent merges multiple defect analysis functions into a single electromagnetic wave measurement process. By analyzing the temporal characteristics of excited carrier recombination, the system simultaneously identifies different defect types (such as deep level and shallow level defects) without requiring separate measurements for each defect category
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 non-contact and non-destructive analysis of defect densities and types in thin films, allowing for real-time monitoring and control of semiconductor processes, thereby improving the quality of thin films.
Implementation Method 1
injecting a laser beam capable of forming excited carriers in a thin film
Implementation Method 2
irradiating an electromagnetic wave onto the thin film while the excited carriers in the thin film are recombining, measuring characteristic information of the electromagnetic wave reacting with the excited carriers
Data Source
AI summary
Provided is a process monitoring method including injecting a laser beam capable of forming excited carriers in a thin film, irradiating an electromagnetic wave onto the thin film while the excited carriers in the thin film are recombining, measuring characteristic information of the electromagnetic wave reacting with the excited carriers in the thin film, and determining whether the thin film is normal, by comparing reference data to a result using the measured characteristic information of the electromagnetic wave.