Glow Discharge Plasma Oxygen Mixture for Organic Sample Analysis

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Solution Overview

Problem

Current glow discharge spectrometry methods face challenges in analyzing organic and polymer samples due to low etching speed, poor etching uniformity, and interference from chemical species, which limits depth resolution and signal quality.

Innovation Solution

Modifying the oxygen concentration in the gaseous mixture during exposure to the glow discharge plasma and applying a radiofrequency electric field with an axial or transverse magnetic field, along with calibration using a known organic sample, to enhance etching speed and signal intensity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a pure argon plasma is used for glow discharge spectrometry, then the etching speed is maximized and the plasma efficiently erodes the sample surface, but certain elements such as fluorine and non-metallic elements are not effectively excited

Engineering Contradiction:
Improveetching speedVSAvoidexcitation efficiency of certain elements
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent changes the chemical composition parameter of the plasma gas from pure argon to an argon-oxygen mixture, where oxygen concentration is optimized at 1-10%. This parameter modification enables effective excitation of fluorine and non-metallic elements while preserving adequate etching performance for the analyzed samples

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses a composite gas mixture of argon and oxygen instead of a single pure gas. This composite approach combines the benefits of argon (adequate etching capability) with oxygen (enhanced excitation of specific elements), creating a plasma environment that addresses multiple analytical requirements simultaneously

Inventive Principle:
Principle #40Composite materials

2Reliability

If a neon or helium plasma is used to increase the ionic or atomic emission lines of certain elements, then the atomic emission of fluorine is increased, but the etching speed decreases significantly

Engineering Contradiction:
Improveatomic emission intensityVSAvoidetching speed
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

Instead of switching to neon or helium gases, the patent modifies the argon plasma composition by adding oxygen at controlled concentrations (1-10%). This parameter change achieves enhanced atomic emission for elements like fluorine while maintaining the high etching speed characteristic of argon-based plasmas, avoiding the significant speed penalty associated with neon or helium

Inventive Principle:
Principle #35Parameter changes

3Reliability

If a mixture of argon and helium is used to increase the intensity of certain atomic emission lines, then the ionization efficiency is increased, but the etching speed does not reach the maximum obtained with pure argon plasma

Engineering Contradiction:
Improveionization efficiencyVSAvoidetching speed
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent changes the gas mixture composition from argon-helium to argon-oxygen, where oxygen concentration is optimized at 1-10%. This parameter modification achieves enhanced ionization efficiency and atomic emission intensity while preserving the maximum etching speed that can be obtained with argon-based plasmas, overcoming the limitation of argon-helium mixtures

Inventive Principle:
Principle #35Parameter changes

4Reliability

If hydrogen is added to argon plasma to increase ionization yields, then the ionization efficiency is improved, but hydrogen species induce emission bands that interfere with atomic or ionized element lines and significantly alter quantitative analysis

Engineering Contradiction:
Improveionization yieldsVSAvoidspectral interference
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent changes the gas composition parameter by replacing hydrogen addition with oxygen addition (1-10% in argon). This parameter modification achieves improved ionization yields and enhanced atomic emission without introducing the spectral interference problems caused by hydrogen species, maintaining clean spectral lines for quantitative analysis

Inventive Principle:
Principle #35Parameter changes

5Productivity

If oxygen is present in the glow discharge spectrometer as an impurity, then parasitic spectral lines are generated, but intentional addition of gaseous oxygen at controlled concentrations increases etching speed and improves signal intensity for organic samples

Engineering Contradiction:
Improveetching speedVSAvoidparasitic spectral lines
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent changes the gas composition parameter by intentionally adding oxygen at controlled concentrations (1-10%) to the argon plasma. This parameter modification achieves significantly improved etching speed and signal intensity for organic samples while maintaining spectral quality through proper concentration control, transforming oxygen from a problematic impurity into a beneficial additive

Inventive Principle:
Principle #35Parameter changes

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 significantly increases etching speed, improves etching uniformity, and enhances the signal-to-noise ratio, enabling precise analysis of organic and polymer samples with better depth resolution.

Implementation Method 1

a sample to be analyzed is exposed to an etching plasma which performs surface ablation

Methodology Applied
Scientific EffectSurface ablation: Ablation

Implementation Method 2

Glow discharge spectrometry is a technique for the elementary and/or molecular analysis of solids

Methodology Applied
Scientific EffectGlow discharge: Electric Glow Discharge

Implementation Method 3

the plasma ensures, via various physico-chemical mechanisms, the excitation and the ionization of the eroded species

Methodology Applied
Scientific EffectExcitation:

Implementation Method 4

the plasma ensures, via various physico-chemical mechanisms, the excitation and the ionization of the eroded species

Methodology Applied
Scientific EffectIonization: Ionisation

Implementation Method 5

The monitoring of the species present in the plasma, respectively by an optical spectrometer for the excited species

Methodology Applied
Scientific EffectOptical emission spectrometry: Absorption Spectroscopy

Implementation Method 6

by a mass spectrometer for the ionized species thus makes it possible to measure the elementary chemical composition

Methodology Applied
Scientific EffectMass spectrometry:

Implementation Method 7

applying a radiofrequency electric field with an axial or transverse magnetic field

Methodology Applied
Scientific EffectMagnetic field coupling: Magnetic Field

Data Source

PatentEP2434275B1Method of measuring a solid organic or polymer sample by luminescent discharge spectrometry
Publication Date: 2016.12.28 HORIBA JOBIN YVON
  • EP2434275B1 patent drawingFigure 1~2
  • EP2434275B1 patent drawingFigure 3
  • EP2434275B1 patent drawingFigure 4

AI summary

The method involves placing a solid sample (3) in a luminescent discharge lamp (2), and injecting gas mixture with rare gas and gaseous oxygen in the lamp. A pulsated radio frequency type electric discharge is applied to electrodes of the lamp to generate luminescent discharge plasma. An organic material layer is exposed to the plasma to obtain imaging speed of the layer greater than imaging speed produced by the plasma in the rare gas without oxygen. A signal representative of ionized and/or excited species of the plasma is measured by a spectrometer (4) e.g. optical emission spectrometer. The inert gas is argon, neon, helium or mixture of the inert gas.