Nozzle Plasma Gas Detection for Radical Reaction Endpoint Sensing
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Solution Overview
Problem
In processing apparatuses, detecting the end point of radical reactions is challenging due to insufficient light emission from plasma, leading to contamination of light collection ports and electrode degradation, and requiring improved S/N ratio and efficient light collection methods.
Innovation Solution
A detecting device with a nozzle structure and dielectric barrier discharge using inert gases like argon and helium to re-excite exhausted gases, forming plasma that efficiently emits light for analysis, while preventing deposits and maintaining electrode integrity through dielectric barrier discharge and inert gas coverage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If OES is used to detect gas components in radical reactions, then the detection system is simple, but the light emission intensity is insufficient and S/N ratio is poor
Solution Approach 1:
The patent introduces a buffer gas (mediator) between the reaction chamber and the detection region. This buffer gas serves as an intermediary that enhances the light emission from the reaction products while maintaining the simplicity of the OES detection system. The buffer gas molecules interact with the excited species from the radical reaction, producing stronger emission signals that improve the S/N ratio without adding complex detection equipment.
2Illumination intensity
If plasma is used to excite exhausted gas for detection, then light emission intensity increases, but light collection ports become contaminated and electrodes degrade
Solution Approach 1:
The patent extracts the harmful reaction components from the detection system by using a separate buffer gas region. The excited species from the radical reaction are allowed to react with the buffer gas in a controlled manner that produces detectable light emission without causing contamination to the light collection ports or degradation of electrodes. This separation of the reaction zone from the detection zone eliminates the harmful effects while preserving the beneficial light emission.
3Measurement precision
If buffer gas is introduced to enhance light emission, then S/N ratio improves, but system complexity increases
Solution Approach 1:
The patent optimizes the buffer gas parameters (flow rate, pressure, composition) to achieve the desired light emission enhancement with minimal system complexity. By carefully controlling these parameters, the system achieves improved S/N ratio without requiring complex gas supply equipment. The buffer gas is introduced at controlled flow rates and pressures that maximize the emission enhancement while using simple, readily available gas handling components.
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 method enables efficient detection of radical reaction progress and endpoint without time lag, improving the signal-to-noise ratio and maintaining system quality and performance by actively introducing exhausted gases into plasma for analysis.
Implementation Method 1
dielectric barrier discharge using inert gases like argon and helium to re-excite exhausted gases, forming plasma that efficiently emits light for analysis
Implementation Method 2
re-excite exhausted gases, forming plasma that efficiently emits light for analysis
Implementation Method 3
a light emission of the generated plasma passes through the hole of the nozzle portion and is detected by a light emission detecting unit
Implementation Method 4
light emissions of the plasma from the chamber are separated (by a wavelength) so that an over-time change in a light emission intensity of a specified gas component is detected
Data Source
AI summary
Provided is a detecting device of gas components that includes a gas component detecting unit for detection of a light emission of plasma that is formed by re-excitation downstream of an arrangement position of an object to be processed. The gas component detecting unit includes an introduced gas supply portion that supplies an introduced gas, a nozzle portion that is provided with a hole through which the introduced gas that is supplied from the introduced gas supply portion passes through and an opening through which a part of a gas to be analyzed flowing through an exhaust pipe portion is introduced into an inside of the hole, the opening being provided in an intermediate portion of the hole, a discharge electrode portion that generates plasma inside the nozzle portion by causing the gas to be analyzed that is introduced from the opening into an inside of the nozzle portion and the introduced gas that is supplied into the inside of the hole to discharge, and a light emission detecting unit that detects a light emission of the plasma generated inside the nozzle portion by the discharge electrode portion.