Semiconductor Wafer Defect Inspection via Coordinate Merging
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Solution Overview
Problem
The miniaturization of semiconductor manufacturing processes has made it challenging to balance high throughput and defect detection accuracy, as microscopic defects are difficult to detect without increasing manufacturing noise and reducing throughput, especially when using optical inspection devices, and existing methods do not effectively address systematic defects.
Innovation Solution
A method that merges hot-spot coordinates with detected defect coordinates from other inspection devices, adding type information, and decides an inspection sequence to select the appropriate inspection method for each coordinate, allowing for high-accuracy defect review and fixed-point inspection with improved throughput by optimizing image capture sequences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If optical inspection device sensitivity is increased to detect microscopic defects, then defect detection capability is improved, but manufacturing noise and false positives increase
Solution Approach 1:
The patent applies local quality by differentiating inspection methods based on defect type. Systematic defects (which have consistent locations and patterns) are inspected using optical inspection devices, while random defects are inspected using SEM. This localized approach to quality control allows each inspection method to be optimized for its specific defect type, improving detection accuracy without increasing false positives from overly sensitive optical inspection across all defect types.
2Measurement precision
If SEM is used to capture high-resolution images of microscopic defects, then measurement precision is improved, but inspection time increases and throughput decreases
Solution Approach 1:
The patent segments the defect inspection process into two distinct pathways: optical inspection for systematic defects and SEM inspection for random defects. By dividing the inspection task based on defect characteristics rather than using a single method for all defects, the system achieves high resolution where needed (SEM for random defects) while maintaining high throughput for the majority of systematic defects detected by optical inspection.
Solution Approach 2:
The patent applies partial action by using SEM only for the subset of random defects that require high-resolution imaging, rather than applying SEM to all defects. Optical inspection handles the larger portion of systematic defects, and SEM is used partially only when higher resolution is necessary, thus optimizing the balance between measurement precision and productivity.
3Measurement precision
If whole surface inspection is performed using SEM, then defect detection accuracy is improved, but inspection time and cost increase significantly
Solution Approach 1:
The patent applies local quality by assigning different inspection methods to different defect types based on their characteristics. Optical inspection is used for systematic defects that have predictable locations and patterns, while SEM is used for random defects. This localized approach ensures high detection accuracy for each defect type without the prohibitive time cost of using SEM for the entire wafer surface.
Data Source
AI summary
A defect inspection method for inspecting a defect on a semiconductor wafer, using plural inspection methods includes: merging hot-spot coordinates as coordinates on the semiconductor wafer, designated by a user, or coordinates where a systematic defect can occur, with detected defect coordinates on the semiconductor wafer, acquired from inspection information, after information indicating the type of coordinates are added thereto; deciding an inspection sequence of the coordinates merged with each other; and defect inspection for executing selection using the information indicating the respective types of the coordinates merged with each other, and executing an inspection by selecting an inspection method for every coordinates to be inspected.