Substrate Color Imaging for CMP Film Non-Uniformity Classification
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing optical metrology systems for CMP processes are inefficient in detecting and classifying film non-uniformity and abnormalities on substrates, leading to potential underpolishing or overpolishing issues.
Innovation Solution
A method utilizing color images of substrates to classify film non-uniformity by determining difference vectors between pixel colors and a standard color, sorting pixels into normal and abnormal regions, and analyzing these regions to determine the type and severity of abnormalities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional optical metrology systems are used to measure film thickness, then measurement precision is improved, but productivity deteriorates due to time-consuming measurements and precise alignment requirements
Solution Approach 1:
The patent replaces traditional mechanical/optical alignment-based metrology systems with a color image processing system. Instead of using complex optical setups requiring precise alignment, the invention uses color camera imaging combined with image processing algorithms to detect and classify film non-uniformity, thereby improving throughput while maintaining detection capability
Solution Approach 2:
The patent changes the measurement parameter from direct thickness measurement to color intensity analysis. By capturing color images and analyzing pixel intensity values across different regions, the system identifies non-uniformity patterns without requiring precise optical alignment or time-consuming thickness measurements at each point
2Measurement precision
If traditional optical metrology systems are used, then measurement precision is improved, but device complexity worsens due to alignment requirements
Solution Approach 1:
The patent replaces complex mechanical alignment systems with a simplified color imaging system. The color camera captures the entire substrate surface without requiring precise alignment, and image processing algorithms automatically identify non-uniform regions through color analysis, eliminating the need for complex alignment mechanisms
Solution Approach 2:
The patent creates a color image copy of the substrate surface and performs analysis on the digital copy rather than requiring direct optical measurement. This allows the system to analyze film uniformity from a captured image without the complexity of aligning measurement beams or sensors with the substrate features
Data Source
AI summary
A method of classification of a film non-uniformity on a substrate includes obtaining a color image of a substrate with the color image comprising a plurality of color channels, obtaining a standard color for the color image of the substrate, for each respective pixel along a path in the color image determining a difference vector between the a color of the respective pixel and the standard color to generate a sequence of difference vectors, sorting the pixels along the path into a plurality of regions including at least one normal region and at least one abnormal region based on the sequence of difference vectors, and classifying the at least one abnormal region as overpolished or underpolished based on at least one difference vector of a pixel at a boundary between the abnormal region and an adjacent normal region.