In-Situ Plasma Uniformity Monitoring for Wafer Drift Detection
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Solution Overview
Problem
In complex semiconductor manufacturing processes, existing ex situ metrology techniques are costly, time-consuming, and wasteful, as they require separate equipment to analyze wafers post-processing, failing to detect system drifts in real-time.
Innovation Solution
The use of computer vision to evaluate plasma uniformity by obtaining signals from camera sensors during plasma-based operations, determining plasma characteristics, and adjusting process conditions in real-time to ensure uniformity of wafer characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If ex situ metrology techniques are used to analyze wafers post-processing, then wafer characteristics can be measured, but the process is costly, time-consuming, and results in wafer waste
Solution Approach 1:
The patent applies preliminary action by performing in-situ plasma uniformity evaluation during the plasma-based operation itself, rather than waiting for post-processing analysis. The camera system captures plasma characteristics in real-time, allowing drift detection to occur before wafer processing completes, thus eliminating the time loss associated with post-processing metrology
Solution Approach 2:
The patent introduces an intermediary measurement approach by using camera sensors to capture plasma characteristics as a proxy for wafer characteristics. Instead of directly measuring the wafer after processing, the system measures plasma uniformity during processing, which serves as an intermediate indicator that predicts final wafer quality without requiring post-processing analysis
2Reliability
If ex situ metrology techniques are used to detect system drift, then drift can be identified, but separate standalone equipment is required and wafers are wasted
Solution Approach 1:
The patent merges the drift detection function directly into the existing plasma processing chamber by integrating camera sensors and analysis systems within the same device. This eliminates the need for separate standalone equipment while maintaining the ability to detect system drift, thereby reducing device complexity
Solution Approach 2:
The plasma processing chamber performs self-diagnosis by using integrated camera sensors to monitor its own plasma uniformity and detect drift conditions. The system serves its own measurement needs without requiring external metrology equipment, enabling real-time drift identification while processing wafers
3Productivity
If real-time plasma monitoring is implemented, then system drift can be detected promptly, but additional in-situ measurement capabilities are required
Solution Approach 1:
The patent replaces complex mechanical measurement systems with optical-based camera sensing. Instead of using physical probes or mechanical sensors within the plasma chamber, the system uses non-contact optical imaging to monitor plasma uniformity, achieving real-time detection while minimizing mechanical complexity
Solution Approach 2:
The patent changes the measurement parameter from direct wafer characteristic measurement to plasma characteristic measurement. By monitoring plasma properties (brightness, uniformity, distribution) instead of directly measuring wafer properties, the system achieves real-time detection capability using simpler optical parameters that can be captured by standard camera sensors
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 allows for real-time control of semiconductor fabrication processes, reducing waste, lowering costs, and improving wafer quality and yield by detecting and correcting system drifts and non-uniformities promptly.
Implementation Method 1
obtain signals from one or more camera sensors optically coupled to one or more optical access apertures of a device fabrication process chamber during performance of a plasma-based operation
Data Source
AI summary
Various embodiments herein relate to apparatuses and methods for evaluating plasma uniformity using computer vision. In some embodiments, a method comprises obtaining signals from one or more camera sensors optically coupled to one or more optical access apertures of a device fabrication process chamber during performance of a plasma-based operation. The method may comprise determining, from the signals, plasma characteristics during the performance of the plasma-based operation. The method may comprise determining, from the plasma characteristics, a non-uniformity of one or more wafer characteristics of a wafer undergoing the plasma-based operation.