Defect Reviewing View Size Selection via Calibration Substrate
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing defect reviewing methods for thin-film devices, such as semiconductor wafers, face inefficiencies in selecting the appropriate view size for defect search and fine alignment due to errors in defect coordinate data, leading to increased user workload and variability in reliability across different operators.
Innovation Solution
A method involving a calibrating substrate with known defects is used to correct errors in defect coordinate data by separating non-random errors from random errors, allowing for the selection of an optimal view size for defect search and fine alignment, thereby improving the efficiency and reliability of the defect reviewing process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If defect coordinate data is used directly from inspection apparatus, then the defect reviewing process can proceed, but errors in coordinate data lead to incorrect view size selection and unreliable fine alignment
Solution Approach 1:
A calibration substrate with known defect positions serves as an intermediary between the inspection apparatus and the defect reviewing process. By measuring defects on this calibration substrate, the system establishes correction values that mediate the coordinate data from the inspection apparatus, thereby improving reliability without sacrificing measurement precision.
Solution Approach 2:
The patent replaces manual trial-and-error methods for view size selection and fine alignment with an automated correction system. The correction values derived from calibration substrate measurements substitute for operator judgment, eliminating variability and improving both reliability and precision consistently across different operators and situations.
2Ease of operation
If manual trial and error method is used for view size selection, then flexibility is maintained, but user workload increases and reliability varies across operators
Solution Approach 1:
The calibration substrate measurement and correction value calculation are performed in advance, before the actual defect reviewing process. This preliminary action establishes the correction parameters that will be automatically applied during routine inspections, eliminating the need for operators to perform time-consuming trial and error adjustments for each defect review while maintaining ease of operation through automated view size selection.
3Measurement precision
If calibration substrate with known defects is used, then coordinate errors can be corrected, but additional processing steps are required
Solution Approach 1:
The calibration substrate creates a copy or replica of the defect coordinate system with known, accurate positions. By measuring defects on this calibrated copy and deriving correction values, the system transfers the precision benefits to the actual defect reviewing process without requiring complex real-time adjustments during routine inspections.
Data Source
AI summary
Absolute coordinates designate position coordinates of a defect of a calibrating substrate, and inspection coordinates designate position coordinates of the defect of the calibrating substrate detected by an inspection apparatus. A deviation of the inspection coordinates with respect to the absolute coordinates is an error included in the inspection coordinates. When “nonrandom errors” are removed from the inspection coordinates, a “random error” is left in the inspection coordinates. The view size for defect search in a defect reviewing apparatus is set based on the random error. Further, a defect for fine alignment is selected based on the tendency of a detected value of the defect size of the calibrating substrate detected by the inspection apparatus.