Measurement Violation Analysis for Upstream Process Abnormality Detection
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Solution Overview
Problem
In manufacturing, particularly in semiconductor fabrication, identifying abnormalities in fabrication processes is laborious and costly due to the need for manual analysis of vast metrology data, and existing statistical process control methods are insufficient to pinpoint upstream faults in complex systems.
Innovation Solution
A method and system that analyze current and historical metrology data to calculate and compare rate of change of parameters, identifying abnormalities by comparing current rates to reference rates, and using this analysis to determine the source of defects within the fabrication process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If statistical process control methods are used to monitor manufacturing processes, then process variation can be controlled and quality can be maintained, but the ability to pinpoint upstream faults in complex systems is insufficient
Solution Approach 1:
The patent segments the manufacturing process into discrete operations and samples, analyzing metrology data at each step individually. By breaking down the complex fabrication process into manageable segments (operations 202A-B, samples 302), the system can identify which specific segment caused the abnormality, thereby pinpointing upstream faults that traditional SPC cannot detect.
Solution Approach 2:
The patent introduces a new dimension of analysis by calculating and comparing rates of change of parameter values across multiple operations and samples. Instead of only monitoring absolute parameter values (traditional SPC), the system analyzes the dimension of change over time, enabling detection of abnormal trends and upstream fault propagation that would be invisible to conventional methods.
2Measurement precision
If manual analysis of metrology data is performed to identify product abnormalities, then detailed inspection can be conducted, but the process becomes laborious and costly
Solution Approach 1:
The patent replaces manual mechanical analysis with an automated computational system that processes metrology data. The system automatically calculates parameter rates of change, compares them across operations and samples, and identifies abnormalities through algorithmic analysis, eliminating the need for laborious manual review while maintaining or improving detection accuracy.
Solution Approach 2:
The system performs self-service by automatically analyzing its own metrology data without external intervention. The automated comparison of rates of change across samples and operations enables the system to identify upstream faults independently, reducing both time and cost while maintaining precision.
3Reliability
If comprehensive metrology data from multiple operations and samples is analyzed to identify upstream faults, then fault detection accuracy improves, but energy consumption and processing resources increase
Solution Approach 1:
The patent extracts only the essential information needed for fault detection by calculating rates of change of parameter values. Instead of processing and analyzing all raw metrology data points, the system extracts the critical metric (rate of change) that indicates upstream faults, significantly reducing computational energy requirements while maintaining high identification accuracy.
Solution Approach 2:
The system performs preliminary analysis by calculating rates of change for all samples and operations in advance, storing these derived values for efficient comparison. This preliminary processing organizes the data in a way that enables quick fault identification without requiring intensive real-time computation, thereby reducing overall energy consumption.
Data Source
AI summary
The subject matter of this specification can be implemented in, among other things, a method, system, and/or device to receive current metrology data for an operation on a current sample in a fabrication process. The metrology data includes a current value for a parameter at each of one or more locations on the current sample. The method further includes determining a current rate of change of the parameter value for each of the one or more locations. The current rate of change is associated with the current sample. The method further includes identifying one or more violating locations each having an associated current rate of change of the parameter value that is greater than an associated reference rate of change of the parameter value, and identifying an instance of abnormality of the fabrication process based on the one or more violating locations.