Semiconductor Sample Cleaving With Pulse Lasers for Low-Damage Defect Analysis
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Solution Overview
Problem
The increasing complexity of semiconductor devices due to integration leads to challenges in inspecting internal defects, particularly when observing structures in a vertical direction, which complicates sample processing and increases the difficulty of defect detection.
Innovation Solution
A sample processing method using a femtosecond or nanosecond pulse laser to form a guide line on a substrate with a (100) crystal plane, allowing for precise cutting and analysis of semiconductor devices while minimizing thermal deformation and damage to the device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional sample processing methods are used, then the processing speed and cost are improved, but thermal deformation and damage to semiconductor devices occur
Solution Approach 1:
The patent changes the processing parameters by using ultrashort pulse lasers (femtosecond or picosecond pulses) instead of conventional continuous or long-pulse lasers. This parameter change enables cold ablation processing where the extremely short pulse duration prevents heat diffusion to surrounding areas, eliminating thermal deformation while maintaining high processing speed
Solution Approach 2:
The patent employs periodic pulsed laser irradiation with specific pulse widths in the femtosecond to picosecond range. This periodic action allows energy to be delivered in discrete bursts that are shorter than the thermal diffusion time, preventing heat accumulation and thermal damage while maintaining efficient material removal
2Ease of manufacture
If conventional laser processing is used, then cutting is achieved, but damage to semiconductor devices occurs
Solution Approach 1:
The patent changes the laser pulse width parameter to ultrashort durations (femtosecond to picosecond range), which enables precise cutting through cold ablation without generating thermal damage that would compromise device integrity
Solution Approach 2:
The patent segments the laser processing into extremely short pulses with sufficient intervals between them, allowing the material to be removed layer by layer through cumulative ablation without thermal diffusion between pulses, thus achieving clean cuts while preserving device integrity
3Difficulty of detecting and measuring
If sample processing is performed to inspect internal defects, then defect detection is enabled, but the complexity of sample processing increases due to aspect ratio
Solution Approach 1:
The patent replaces conventional mechanical cutting methods with ultrashort pulse laser ablation, eliminating the need for complex mechanical sample preparation procedures. This substitution simplifies the sample processing workflow while enabling efficient inspection of internal defects in high-aspect-ratio structures
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 method enables fast and cost-effective sample processing and analysis, reducing thermal deformation and minimizing damage to semiconductor devices, facilitating efficient defect inspection.
Implementation Method 1
forming a guide line that extends in a first direction by irradiating the first surface of the sample with a laser
Implementation Method 2
forming a guide line that extends in a first direction by irradiating the first surface of the sample with a laser
Implementation Method 3
forming an opening in the substrate by irradiating a top surface of the substrate with a laser
Data Source
AI summary
Sample processing methods and semiconductor device analysis methods are provided. A sample processing method includes: preparing a sample that has a first surface and a second surface that are opposite to each other; forming a guide line that extends in a first direction by irradiating the first surface of the sample with a laser, and destroying the sample along the guide line, wherein the sample includes a substrate that has a bottom surface that extends parallel to the first direction, the bottom surface of the substrate has a (100) crystal plane, and the laser includes a femtosecond pulse laser or a nanosecond pulse laser.