Wafer Inspection Optical Condition Setting Using Similar Pattern Search
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for automatically setting the optical conditions in critical dimension scanning electron microscopes (CD-SEM) require observation images of the wafer, limiting their applicability without the wafer present and failing to provide optimal conditions at positions other than the captured one.
Innovation Solution
A database is used to associate inspection apparatus and sample models, allowing for the prediction and quick setting of optical conditions by searching for similar image data and extracting candidates based on priority orders, enabling the creation of an analysis model before the customer wafer is obtained.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If automated optical condition setting is implemented using observation images, then the need for manual adjustment is reduced, but the method cannot be applied unless the wafer is obtained and limited to the captured position
Solution Approach 1:
The patent creates an analysis model in advance that predicts optimal optical conditions for different wafer positions and observation conditions. By pre-calculating and storing the relationship between observation positions, wafer specifications, and optimal optical conditions in a database, the system enables automated setting without requiring actual wafer presence or position-specific image capture, thus resolving the contradiction between automation and adaptability
2Manufacturing precision
If manual adjustment of optical conditions is performed by specialized companies, then optimal conditions are achieved, but production efficiency deteriorates due to CD-SEM stoppage
Solution Approach 1:
The patent enables the CD-SEM to automatically determine optimal optical conditions by itself using the pre-created analysis model and database. The system extracts wafer specification information, queries the database for corresponding optimal conditions, and applies them without external intervention. This self-service capability eliminates the need for specialized company adjustments, maintaining manufacturing precision while preventing production stoppage
3Measurement precision
If optical conditions are adjusted for different wafer types, then measurement accuracy is improved, but the adjustment work becomes complicated and time-consuming
Solution Approach 1:
The patent creates a virtual analysis model that copies and simulates the optical conditions for different wafer types and observation positions. Instead of performing complex manual adjustments for each wafer type, the system uses pre-stored optimal condition data from the analysis model, significantly reducing adjustment complexity while maintaining measurement precision through accurate condition matching
Data Source
AI summary
Disclosed is a solution for quickly specifying an optical condition of a wafer to be inspected, and in particular, accelerating optical condition setting after obtaining a customer wafer. An inspection apparatus automatic adjustment system according to the present invention includes an analysis-condition-setting interface that inputs analysis conditions; an analysis-execution unit that performs analysis; an inspection-device model and model DB used for analysis; an analysis-result DB that stores analysis results; an observation-condition setting interface that inputs a wafer pattern, a focus point, an optimization index, and a priority; a wafer-pattern search unit that searches for a wafer pattern similar to the input wafer pattern; an optical-condition-extraction unit that extracts, from the analysis result DB, the optimum optical condition for the similar wafer pattern and the focus point; and an optical-condition-setting unit that generates a control signal corresponding to the optical condition and transmits the control signal to the inspection apparatus.