Programmable RF Plasma Irregularity Detection Using Machine Learning

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Solution Overview

Problem

Current digital signal processing in radio-frequency systems for plasma systems faces inefficiencies due to interference suppression methods that can miss irregularities like secondary plasma or arcs, leading to potential damage in semiconductor processing, and existing solutions require abnormalities to be present before detection can occur.

Innovation Solution

A method utilizing machine learning to optimize digital signal processing by training a programmable circuit, such as an FPGA, with reference data to detect irregularities in real-time, allowing for proactive prevention of arcs and other plasma instabilities through optimized parametrization and pattern recognition.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If filtering is used to suppress interferences in RF signals, then measurement quality is improved, but detection of irregularities like secondary plasma or arcs is reduced

Engineering Contradiction:
Improvemeasurement qualityVSAvoiddetection of irregularities
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent segments the signal processing into multiple stages: initial filtering to remove strong interferences, followed by machine learning-based analysis to detect irregularities in the remaining signal. This segmentation allows each stage to optimize for its specific function without compromising the other.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the parameter configuration of filters based on the specific interference conditions and signal characteristics. By dynamically adjusting filter parameters such as cutoff frequencies and bandwidths, the system maintains measurement quality while preserving irregularity detection capability.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If filter parameters are optimized to reduce interference, then signal reconstruction is improved, but response time to deviations is reduced

Engineering Contradiction:
Improvesignal reconstructionVSAvoidresponse time
Core Design Contradiction:
Measurement precisionVSSpeed

Solution Approach 1:

The patent implements dynamic filter parameter adjustment where the filter characteristics are continuously adapted based on real-time signal conditions. This allows the system to maintain optimal signal reconstruction while responding quickly to deviations, as the filter parameters are not fixed but dynamically optimized.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system uses feedback from the machine learning analysis of signal deviations to adjust filter parameters in real-time. When irregularities are detected or anticipated, the filter parameters are modified to improve response time while maintaining reconstruction quality.

Inventive Principle:
Principle #23Feedback

3Stability of the object's composition

If filtering is applied to remove interferences, then output power measurement stability is improved, but detection of plasma instabilities is reduced

Engineering Contradiction:
Improvemeasurement stabilityVSAvoiddetection of plasma instabilities
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The patent applies preliminary filtering to remove known interference patterns before the signal is used for measurement and analysis. By pre-removing these interferences, the subsequent machine learning analysis can focus on detecting plasma instabilities without being confounded by the filtered-out interference patterns.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The machine learning algorithm acts as an intermediary between the filtered signal and the final detection output. It analyzes the filtered signal to detect plasma instabilities, effectively bridging the gap between interference suppression and irregularity detection.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Reliability

If dedicated detection solutions are used for specific irregularities, then detection reliability is improved, but adaptability to different irregularity types is reduced

Engineering Contradiction:
Improvedetection reliabilityVSAvoidadaptability to irregularity types
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent implements a universal machine learning-based detection system that can identify multiple types of irregularities (arcs, secondary plasma, instabilities) using a single integrated approach. The system is trained on diverse data to recognize various irregularity patterns, making it adaptable to different irregularity types while maintaining high detection reliability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The machine learning system continuously learns from incoming signal data, automatically adapting its detection capabilities to new irregularity types without requiring manual reconfiguration. This self-learning capability enhances both reliability and adaptability over time.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP4113574B1Method for machine learning a detection of at least one irregularity in a plasma system
Publication Date: 2024.01.03 COMET AG
  • EP4113574B1 patent drawingFigure 1a
  • EP4113574B1 patent drawingFigure 1b
  • EP4113574B1 patent drawingFigure 2

AI summary

The invention relates to a method for machine learning a detection of at least one irregularity in a plasma system, particularly an RF powered plasma processing system, comprising: - Providing at least one input signal (210) each related to an analog signal of a power delivery system (1) for the plasma system and/or to another characteristic of the power delivery system (1) and/or of the plasma system, the at least one input signal (210) having at least one irregularity feature indicative of the irregularity in the plasma system, - Performing a machine learning procedure (310) wherein the at least one input signal (210) having the at least one irregularity feature is processed by a programmable circuit (10) to train the detection of the irregularity in the plasma system.