Nitrogen-Free Ozone Generator Cooling and Purity

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Solution Overview

Problem

Conventional ozone gas supply systems for semiconductor manufacturing introduce metal contaminants and nitric acid by-products, leading to corrosion and oxidation issues, and require large spaces and high costs due to the need for nitrogen-added oxygen gas and complex piping systems.

Innovation Solution

A nitrogen-free ozone generating unit that uses high-purity oxygen gas without nitrogen, employing a photocatalyst with a specific band gap and a heat insulating layer to cool the ozone generator, thereby preventing condensation and enhancing ozone generation efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If nitrogen gas is added to oxygen gas to increase ozone generation efficiency, then ozone generation efficiency is improved, but metal contaminants and nitric acid by-products are generated causing corrosion and oxidation issues

Engineering Contradiction:
Improveozone generation efficiencyVSAvoidmetal contaminants and nitric acid by-products
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The invention extracts and removes nitrogen from the raw material gas, using only high-purity oxygen (99.999% or higher). This eliminates the source of nitric acid by-products and metal contaminants while maintaining ozone generation through pure oxygen discharge

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention changes the composition parameter of the raw material gas from nitrogen-containing oxygen (conventional) to ultra-high-purity nitrogen-free oxygen. This parameter change eliminates harmful by-products while achieving efficient ozone generation through controlled discharge

Inventive Principle:
Principle #35Parameter changes

2Productivity

If nitrogen-added oxygen gas is used for ozone generation, then ozone generation efficiency is improved, but system complexity and space requirements increase due to complex piping systems

Engineering Contradiction:
Improveozone generation efficiencyVSAvoidpiping system complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The invention extracts nitrogen from the gas mixture, using only pure oxygen as feed gas. This simplifies the gas supply system by eliminating the need for complex nitrogen addition equipment and multi-path piping systems required for nitrogen-containing oxygen gas

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention merges the ozone generation function with ultra-high-purity oxygen supply, eliminating the need for separate nitrogen addition systems. The integrated approach using pure oxygen simplifies the overall system architecture and reduces piping complexity

Inventive Principle:
Principle #5Merging (Combining)

3Manufacturing precision

If high-purity oxygen gas with low nitrogen content is used, then metal contaminants are reduced, but ozone generation efficiency decreases

Engineering Contradiction:
Improveozone purityVSAvoidozone generation efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The invention changes the oxygen purity parameter to ultra-high-purity level (99.999% or higher) and applies controlled discharge conditions. This parameter optimization enables efficient ozone generation from pure oxygen without requiring nitrogen addition, achieving both high purity and high efficiency

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention substitutes the chemical catalysis mechanism (using nitrogen dioxide from nitrogen addition) with a direct discharge ionization mechanism. By applying electrical discharge to ultra-high-purity oxygen, ozone is generated efficiently without relying on nitrogen-based catalytic pathways

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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

The solution generates highly concentrated, pure ozone without nitrogen by-products, reducing metal contamination and system size, while improving ozone generation efficiency and reducing costs by integrating the ozone generator, power source, and control unit into a single, compact unit.

Implementation Method 1

a cooling medium inlet/outlet is formed to serve as a supply inlet and discharge outlet of a low-temperature cooling medium

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 2

a heat insulating layer made of a heat insulating material is formed to cover a predetermined constituent surface where condensation is likely to occur

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 3

wherein a photocatalyst is applied to a discharge surface, and light having energy greater than a band gap of the photocatalyst is introduced into a discharge region

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Implementation Method 4

Ionization reaction of nitrogen molecules N2 + e ⇒ 2N

Methodology Applied
Scientific EffectIonization: Ionisation

Implementation Method 5

highly concentrated ozone is generated by a catalytic reaction of a trace amount of NO2 generated by a discharge reaction

Methodology Applied
Scientific EffectCatalysis: Catalysis

Data Source

PatentEP2765116B1Ozone generation unit with less nitrogen added
Publication Date: 2021.08.11 TOSHIBA MITSUBISHI ELECTRIC IND SYST CORP
  • EP2765116B1 patent drawingFigure 1
  • EP2765116B1 patent drawingFigure 2
  • EP2765116B1 patent drawingFigure 3

AI summary

In the present invention, a nitrogen-free ozone generating unit (7) integrates a plurality of functional means into a single package unit, the functional means including a nitrogen-free ozone generator (1) that is cooled to a low temperature, an ozone power source (2), a MFC (3), an APC (4), a heat insulating cooling water inlet pipe (31I), and a heat insulating cooling water outlet pipe (310). In the nitrogen-free ozone generator 1, a heat insulating layer 8 made of a heat insulating material such as an insulator is formed to cover substantially the entire surface of an ozone generator outer frame (1x). A cooling water system (30) is configured to set the temperature of cooling water (33), which is supplied to the nitrogen-free ozone generator (1) through the heat insulating cooling water inlet pipe (31I), to 5°C or less and to thereby cool the nitrogen-free ozone generator (1).