Semiconductor Hotspot Detection via SEM Image Comparison
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Solution Overview
Problem
Current methods for monitoring semiconductor manufacturing processes are inadequate in identifying and managing hotspots and process monitoring points, leading to difficulties in controlling defects and maintaining manufacturing quality due to limitations in defect detection and throughput.
Innovation Solution
A system and method utilizing a scanning electron microscope (SEM) to acquire and compare SEM images of semiconductor wafers under different process conditions, extracting process monitoring points with narrow manufacturing margins, and performing high-resolution shape inspection and measurement to identify and manage these points effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If exhaustive managing of all management points is performed, then manufacturing precision is improved, but productivity deteriorates due to the large number of points requiring evaluation
Solution Approach 1:
The patent segments the large number of management points into two categories: hotspots (critical points with narrow process margins) and non-hotspots. By focusing monitoring resources only on hotspots, the system maintains manufacturing precision while improving productivity, as evaluating all points exhaustively is no longer required.
Solution Approach 2:
The patent applies local quality by differentiating the monitoring intensity and resources allocated to different regions of the semiconductor wafer. Hotspots receive focused, high-resolution monitoring, while non-hotspot areas receive reduced or no monitoring, optimizing the balance between precision and productivity.
2Productivity
If samples are selected to reduce the number of evaluation objects, then productivity is improved, but measurement precision deteriorates due to insufficient sampling
Solution Approach 1:
The patent changes the parameter of sample selection from random or arbitrary selection to selection based on process margin parameters. By identifying and monitoring only those points with narrow process margins (hotspots), the system ensures measurement precision is maintained while productivity improves through reduced sampling scope.
3Manufacturing precision
If high magnification SEM imaging is performed on all regions, then manufacturing precision is improved, but loss of time increases due to the extensive imaging required
Solution Approach 1:
The patent extracts and isolates only the critical hotspots from the entire semiconductor wafer for high magnification imaging. By removing non-critical regions from the inspection scope, the system maintains manufacturing precision for critical areas while significantly reducing the time loss associated with imaging all regions.
4Ease of operation
If conventional defect inspection methods are used, then ease of operation is maintained, but measurement precision deteriorates due to inability to detect systematic defects
Solution Approach 1:
The patent implements feedback by comparing measured pattern dimensions at hotspots against target specifications and using this information to adjust and optimize the manufacturing process. This feedback mechanism improves measurement precision for detecting systematic defects while maintaining ease of operation through automated comparison and analysis.
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 efficient identification and management of process monitoring points, improving defect detection and manufacturing control by extracting and evaluating regions with significant process differences, thereby enhancing manufacturing process stability and quality.
Implementation Method 1
irradiate a convergent beam of electrons onto a semiconductor and detect electrons emitted from the irradiated position
Data Source
AI summary
A hotspot searching apparatus manufactures a small number of chips or regions on a semiconductor wafer under respectively different manufacturing process conditions, compares SEM images of their external appearances to output a point having large differences as a narrow process window, that is, a process monitoring point that should be managed in mass production, the narrow process window having a narrow manufacturing process condition (exposure condition) in the manufacturing of the semiconductor wafer, and sets the point as a measurement point by a CD-SEM apparatus, such that it extracts and determines plural circuit pattern parts having a narrow manufacturing process margin as the process monitoring point in a short time and a process monitoring point monitoring performs shape inspection or shape length measurement in detail at high resolution.