SEM Panoramic Imaging for Wide-Range Pattern Measurement
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Solution Overview
Problem
Current methods for predicting and simulating semiconductor pattern shapes transferred to a wafer face challenges due to the dissociation between design information and actual mask patterns, leading to simulation errors, with existing scanning electron microscopes (SEMs) struggling to produce high-magnification images covering wide ranges without degrading image resolution or reducing field of view.
Innovation Solution
A scanning electron microscope device and method that divide a wide imaging area into local segments, allowing high-magnification imaging and joining of overlapping edge information to create a panoramic image, with automatic determination of segment arrangements and imaging magnifications to achieve high-precision pattern dimension measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If imaging is performed at high magnification to maintain image resolution, then image resolution is improved, but field of view is reduced and wide-range imaging becomes difficult
Solution Approach 1:
The patent divides the wide imaging area into multiple local areas (first local area, second local area, etc.) that can be imaged at high magnification separately. Each local area is imaged independently at high magnification to maintain resolution, then the individual images are joined through image processing to create a comprehensive panoramic image of the entire wide area, thus resolving the contradiction between high magnification and wide field of view.
Solution Approach 2:
The patent merges multiple high-magnification images of adjacent local areas through image processing to produce a single panoramic image that covers the entire wide imaging area. By combining the strengths of high-magnification imaging across multiple segments, the system achieves both high resolution and wide coverage simultaneously.
2Measurement precision
If manual composition of imaging recipe is performed to ensure accurate adjustment points and registration templates, then imaging precision is improved, but labor intensity and time consumption increase
Solution Approach 1:
The patent enables the imaging system to automatically determine adjustment points (addressing point, autofocus point, auto-stigma point, auto-brightness/contrast point) and registration templates by utilizing design information and automatically composing the imaging recipe. The system serves itself by automatically identifying key imaging parameters without requiring manual operator intervention, thus maintaining imaging precision while dramatically improving productivity.
Solution Approach 2:
The patent performs preliminary determination of adjustment points and registration templates based on design information before actual imaging. By pre-calculating and setting these critical parameters using available design data, the system eliminates the need for time-consuming manual setup and trial imaging, thereby maintaining precision while accelerating the workflow.
3Quantity of substance
If the number of evaluation points is increased to cover finer and more complex patterns, then measurement coverage is improved, but recipe composition complexity and time increase
Solution Approach 1:
The patent enables automatic composition of imaging recipes that can handle a large number of evaluation points by utilizing design information to automatically determine imaging parameters, adjustment points, and registration templates for each point. The system self-configures the complex recipe structure without manual intervention, allowing comprehensive coverage of numerous evaluation points while keeping the recipe composition process simple and automated.
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 the acquisition of high-resolution, wide-range panoramic images, allowing for precise simulation and feedback in semiconductor fabrication, improving yield by accurately measuring pattern dimensions and correcting fabrication errors.
Implementation Method 1
a scanning electron microscope that sequentially images a plurality of adjoining areas on a specimen according to an imaging recipe composed by a processor while superposing parts of the adjoining areas, thereby acquiring a plurality of images
Implementation Method 2
a scanning electron microscope device including a scanning electron microscope, a processor that composes an imaging recipe for imaging a specimen
Data Source
AI summary
In a panoramic image construction technology a wide-range imaging area (EP) of semiconductor patterns is divided into a plurality of imaging areas (SEP), and joined a group of images, which are obtained by imaging the SEPs using an SEM, through image processing. Although a pattern serving as a key to joining is not contained in an overlap area between some of the SEPs, all the images can be joined in some cases is noted so that: although the number of patterns serving as keys to joining is small, SEPs whose images are all joined can be determined; or even if such SEPs cannot be determined, SEPs satisfying user's request items as many as possible can be determined. The cases are extracted by optimizing an SEP arrangement, whereby the number of cases in which SEPs whose images are all joined can be determined is increased.