Defect Review Apparatus Optimizing Imaging Sequence
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current defect review apparatuses, such as review SEMs, face challenges in achieving high throughput due to time-consuming stage movements and inadequate selection of defect detection methods based on sample characteristics, leading to inefficiencies in defect detection and analysis in semiconductor manufacturing.
Innovation Solution
The method involves using design information about the circuit pattern on semiconductor wafers to select and set up appropriate defect detection methods, such as reference-less, history comparison, and die comparison methods, and optimizing the imaging sequence to minimize stage movement and image acquisition time, allowing for automated setup of defect detection processes without initial image pickup.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the defect inspection apparatus reduces the amount of image data by maximizing the pixel size (lowering the resolution), then the processing speed is improved, but the ability to precisely identify defect type deteriorates
Solution Approach 1:
The inspection process is divided into two distinct stages: a first inspection apparatus performs rapid low-resolution screening to identify defect coordinates, while a second inspection apparatus performs detailed high-resolution analysis on detected defects. This segmentation allows each stage to be optimized independently - speed for the first stage and precision for the second stage - resolving the contradiction between processing speed and defect identification precision.
2Reliability
If the defect review apparatus performs stage movements to acquire images at defect coordinates, then the defect review function is achieved, but the throughput is reduced
Solution Approach 1:
The first inspection apparatus performs preliminary inspection across the entire wafer surface to detect defect coordinates before the second inspection apparatus performs detailed analysis. By pre-identifying defect locations and coordinates, the system avoids unnecessary stage movements and image acquisitions in defect-free areas, thereby maintaining high throughput while ensuring reliable defect review functionality.
Solution Approach 2:
The system extracts only the essential information (defect coordinates and basic characteristics) from the first inspection stage and passes it to the second inspection apparatus. This extraction allows the second apparatus to focus its resources solely on analyzing detected defects without needing to re-inspect the entire wafer, thus maintaining high throughput while achieving reliable defect review.
3Measurement precision
If the defect review apparatus uses high-resolution imaging to review defect details, then the defect analysis accuracy is improved, but the time required for defect analysis increases
Solution Approach 1:
The system applies different imaging qualities to different regions: low-resolution imaging is used for the entire wafer surface during the first inspection stage, while high-resolution imaging is applied only to specific defect regions identified during that stage. This local quality approach ensures high defect analysis accuracy where needed while minimizing the time and resources spent on imaging, as the majority of the wafer surface is inspected at lower resolution.
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
This approach enables consistent and efficient defect review at high throughput by automating the selection of defect detection methods and optimizing imaging sequences, reducing the time required for defect analysis and improving the overall efficiency of the defect review process.
Implementation Method 1
a defect review apparatus based on a scanning electron microscope (hereinafter referred to as the review SEM) has been widely used in recent years
Data Source
AI summary
Disclosed is a method for reviewing defects in a large number of samples within a short period of time through the use of a defect review apparatus. To collect defect images steadily and at high throughput, a defect detection method is selected before imaging and set up for each of review target defects in the samples in accordance with the external characteristics of the samples that are calculated from the design information about the samples. The defect images are collected after an imaging sequence is set up for the defect images and reference images in such a manner as to reduce the time required for stage movement in accordance with the defect coordinates of the samples and the selected defect detection method.