Outgassing Rate Detection Using Electromagnetic Wave Absorption
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Solution Overview
Problem
Existing workpiece processing systems, such as plasma doping and beam-line ion implanters, face instability and non-repeatability due to high outgassing rates from wafers, leading to contamination and arcing issues, which conventional pressure sensors fail to accurately and timely detect.
Innovation Solution
A workpiece processing system that includes a platen, a source providing an electromagnetic wave near the workpiece, and a detector to sense the outgassing rate of byproducts, allowing for real-time adjustment of the dose rate to maintain stable implant conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional pressure sensor is used to detect outgassing rate, then the system can monitor pressure changes, but the detection accuracy and response time are insufficient due to the sensor being positioned far from the workpiece
Solution Approach 1:
The patent positions the electromagnetic wave source and detector in close proximity to the workpiece surface, creating a localized detection zone. This local positioning allows the system to measure outgassing rates at the actual source rather than from a distant location, thereby improving measurement precision and reducing detection time delay.
Solution Approach 2:
The patent introduces electromagnetic waves as an intermediary medium to detect outgassing byproducts. Instead of directly measuring pressure changes with a physical sensor, the system uses electromagnetic wave absorption characteristics of the outgassing byproducts to infer the outgassing rate, achieving more accurate and timely detection.
2Productivity
If the ion dose rate is increased to improve throughput, then production efficiency increases, but outgassing from the workpiece is exacerbated leading to unstable conditions and contamination
Solution Approach 1:
The patent implements a feedback control system where the detector continuously monitors the outgassing rate by measuring electromagnetic wave absorption. The system uses this real-time information to adjust the ion dose rate, automatically reducing it when outgassing increases and increasing it when conditions are stable, thereby maintaining reliable implant conditions while optimizing throughput.
Solution Approach 2:
The patent makes the ion dose rate dynamic rather than static. The system continuously adjusts the dose rate based on real-time outgassing conditions detected by the electromagnetic wave sensor, allowing the processing parameters to adapt to changing workpiece states and maintain stability throughout the implantation process.
3Productivity
If high dose rate ion implantation is performed, then throughput increases, but contamination and arcing issues occur due to high outgassing rates
Solution Approach 1:
The feedback control system detects outgassing byproducts through electromagnetic wave absorption and automatically adjusts the ion dose rate to prevent harmful effects. When outgassing reaches levels that could cause contamination or arcing, the system reduces the dose rate proactively, eliminating these harmful effects while maintaining optimal throughput.
Solution Approach 2:
The system takes preliminary action by detecting outgassing trends before they reach critical levels that would cause contamination or arcing. The feedback control mechanism anticipates potential problems and adjusts the dose rate in advance, preventing harmful effects rather than reacting to them after they occur.
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 solution enables precise control of outgassing rates, improving throughput, reducing contamination, and preventing arcing by modulating the ion dose rate based on real-time detection signals, thereby enhancing the reliability and consistency of the processing system.
Implementation Method 1
a source configured to provide an electromagnetic wave proximate a front surface of the workpiece, and a detector configured to receive at least a portion of the electromagnetic wave and provide a detection signal representative of an outgassing rate
Data Source
AI summary
A workpiece processing system includes a platen configured to support a workpiece, a source configured to provide an electromagnetic wave proximate a front surface of the workpiece, and a detector. The detector is configured to receive at least a portion of the electromagnetic wave and provide a detection signal representative of an outgassing rate from the workpiece of outgassing byproducts. A method of detecting an outgassing rate is also provided. The method includes providing an electromagnetic wave proximate a front surface of a workpiece, receiving at least a portion of the electromagnetic wave, and providing a detection signal representative of an outgassing rate from the workpiece of outgassing byproducts.