Substrate Neutralization via Vacuum UV Ozone Generation
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Solution Overview
Problem
Existing substrate processing apparatuses struggle to completely neutralize substrates with electrical potentials around 10(V) to 0(V), leading to processing defects due to electrification.
Innovation Solution
A substrate processing apparatus that includes a neutralizer using vacuum ultraviolet rays and oxygen molecules to decompose into ozone, which then neutralizes the substrate by breaking its electrical potential to near 0(V), combined with a coater for forming a processing liquid film and a controller for adjusting ozone generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If an ionizer using AC voltage between electrodes is used to neutralize the substrate, then the electrical potential can be reduced from about 1000(V) to about 100(V), but the electrical potential cannot be reduced from about 10(V) to close to 0(V)
Solution Approach 1:
The invention changes the neutralization mechanism from electrical field-based (ionizer) to photochemical-based (vacuum UV irradiation). By irradiating the substrate with vacuum UV rays in an oxygen atmosphere, ozone is generated in situ and adheres to the substrate surface, enabling complete neutralization from 10(V) to 0(V) through a different physical-chemical pathway that overcomes the limitations of electrode-based ionizers
2Productivity
If the substrate is not completely neutralized, then processing can proceed, but processing defects occur due to electrification
Solution Approach 1:
The invention replaces the mechanical/electrical ionizer system with a photochemical system using vacuum UV irradiation. This substitution generates ozone through photodissociation of oxygen molecules, which then chemically neutralizes residual charges on the substrate surface, eliminating processing defects while maintaining continuous processing capability
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
Effectively prevents processing defects caused by electrification by ensuring the substrate's electrical potential is close to 0(V), allowing for uniform neutralization and defect-free coating processing.
Implementation Method 1
part of the vacuum ultraviolet rays is absorbed by the atmosphere including oxygen molecules. The atmosphere above the one surface of the substrate absorbs part of the vacuum ultraviolet rays, whereby an oxygen molecule included in the atmosphere is decomposed into two oxygen atoms by photodissociation
Implementation Method 2
When the generated ozone comes into contact with the one surface of the electro-positive substrate or the electro-negative substrate, electrical charge is given and received between the ozone and the substrate. In this case, the coordinate bond of the ozone is broken, and an electrical potential of the substrate becomes close to 0 (V)
Data Source
AI summary
In a substrate processing apparatus, neutralization processing is performed on a substrate by a neutralization device provided in a thermal processing section. In the neutralization device, at least one of a holder that holds the substrate and an emitter that emits vacuum ultraviolet rays is moved relative to another one in one direction. At this time, one surface of the substrate is irradiated with the vacuum ultraviolet rays emitted by the emitter. When the entire one surface of the substrate is irradiated with the vacuum ultraviolet rays, the neutralization processing ends. Thereafter, the substrate on which the neutralization processing has been performed is transported to a coating processing unit in a coating processing section. In the coating processing unit, a film of a processing liquid is formed on the one surface of the substrate on which the neutralization processing has been performed.