Processor System for Non-Destructive Wafer Cross-Section Shape Estimation
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Solution Overview
Problem
Current semiconductor inspection methods face challenges in efficiently and cost-effectively evaluating changes in three-dimensional cross-sectional shapes across a wafer surface without destructive cross-sectional observations, particularly in determining optimal observation locations and ensuring accurate data coverage.
Innovation Solution
A processor system that acquires and processes electron microscope images to calculate feature data, converts it into a cross-sectional shape index using statistical values, allowing for non-destructive evaluation of cross-sectional shape changes and optimal observation location selection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If cross-sectional observation is performed using destructive methods (FIB processing), then measurement precision of cross-sectional shape is improved, but manufacturing cost increases and productivity decreases
Solution Approach 1:
The patent creates a three-dimensional shape estimation model that copies the cross-sectional shape information from top-view SEM images without requiring physical cross-sectional observation. This virtual copy allows multiple evaluations to be performed on the same sample without destruction, significantly improving productivity while maintaining measurement precision through statistical analysis of multiple measurement locations.
Solution Approach 2:
The patent replaces the mechanical destructive FIB processing system with an information-processing-based estimation system. By substituting physical destruction with computational estimation from top-view images, the system eliminates the need for sample destruction while obtaining cross-sectional shape data, thereby improving both productivity and sample preservation.
2Reliability
If cross-sectional observation is performed at multiple locations, then reliability of cross-sectional shape evaluation is improved, but manufacturing cost and time consumption increase
Solution Approach 1:
The patent performs preliminary selection of measurement locations by analyzing top-view SEM images to identify regions with significant cross-sectional shape changes. This preliminary action allows the system to focus subsequent cross-sectional observations only at critical locations, reducing the total number of observations needed while maintaining evaluation reliability.
Solution Approach 2:
The patent divides the wafer surface into multiple measurement locations and performs statistical analysis on the three-dimensional shape changes across these segmented regions. This segmentation approach allows comprehensive evaluation of cross-sectional shape uniformity across the entire wafer while managing the complexity of multiple measurements through systematic data processing.
3Ease of operation
If representative width is measured from Top-view image only, then ease of operation is improved, but measurement precision of three-dimensional shape is insufficient
Solution Approach 1:
The patent extracts three-dimensional shape information from two-dimensional top-view SEM images by analyzing the relationship between top-view dimensions and cross-sectional shapes. This dimensionality transformation allows the system to obtain precise three-dimensional shape data while maintaining the operational simplicity of top-view image measurement, eliminating the need for complex cross-sectional observation procedures.
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 and cost-effective evaluation of cross-sectional shape changes across a wafer surface, reducing redundant observations and improving data accuracy by quantitatively assessing shape uniformity and variations.
Implementation Method 1
acquire one or more images captured by an electron microscope
Data Source
AI summary
To provide a technique capable of quantitatively grasping a change in three-dimensional shape including a cross-sectional shape of a pattern within a surface of a wafer or between wafers in a non-destructive manner before cross-sectional observation. A processor system of a semiconductor inspection system acquires images captured by an electron microscope (SEM) for a sample (S102), calculates, for a reference region defined on a surface of the sample, first feature data corresponding to each of a plurality of locations in the reference region from the captured image (S103A), calculates a first statistical value based on the first feature data at the plurality of locations (S103B), calculates, for each of a plurality of evaluation regions defined as points or regions on the surface of the sample in correspondence with the reference region, second feature data corresponding to each of one or more locations in the evaluation region from the captured image, as feature data of the same type as the first feature data (S104A), and converts the second feature data using the first statistical value to obtain second feature data after conversion (S105).