UV Tube Apparatus for Liquid Preconditioning
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Solution Overview
Problem
Existing apparatuses for treating photomasks and semiconductor wafers with UV radiation and liquid media do not effectively precondition the liquid medium before application, leading to inefficient generation and decomposition of reactive species, which can result in undesired reactive species reaching the substrate.
Innovation Solution
An apparatus with a housing and tube element that emits UV radiation in specific wavelength ranges to precondition the liquid medium, allowing for tailored generation or decomposition of reactive species, featuring different transmission characteristics for distinct sections to control radiation emission and distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If UV radiation is introduced into the liquid medium to generate radicals for substrate treatment, then cleaning effectiveness is improved, but undesired reactive species may reach the substrate causing harmful effects
Solution Approach 1:
The apparatus divides the UV radiation source into multiple sections along the liquid flow path, with each section emitting at different wavelengths. This segmentation allows the liquid to be sequentially exposed to different radiation types, generating desired radicals while decomposing undesired species at appropriate stages
Solution Approach 2:
The system changes the wavelength parameter of UV radiation along the flow path. By using shorter wavelengths (e.g., 185 nm) in upstream sections and longer wavelengths (e.g., 254 nm) in downstream sections, the liquid medium undergoes different photochemical reactions at different positions, optimizing radical generation while eliminating harmful species
2Device complexity
If the liquid medium is applied directly to the substrate without preconditioning, then the process is simpler, but reactive species are not effectively controlled leading to reduced treatment precision
Solution Approach 1:
The apparatus performs preliminary treatment of the liquid medium by passing it through the UV-radiated flow channel before application to the substrate. This preconditioning step generates and controls reactive species in advance, ensuring optimal treatment conditions are established before the liquid contacts the substrate
Solution Approach 2:
The UV-irradiated liquid medium acts as an intermediary between the UV source and the substrate. The liquid is transformed by UV radiation into a reactive state that can selectively interact with the substrate, mediating the treatment process with controlled precision
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 solution enables a two-step process for generating radicals, ensuring that reactive species are effectively produced and applied to the substrate while minimizing the presence of undesired species, thereby enhancing the cleaning efficiency and specificity of the treatment process.
Implementation Method 1
at least one UV-radiation source in the tube element, which is arranged to emit UV-radiation in the direction of the flow space and through the outlet opening out of the housing
Implementation Method 2
radiation primarily in the wavelength range below 200 nm, in particular primarily in the range about 185 nm, can be introduced into the flow space. In this range, the radiation is particularly suitable for decomposing a liquid medium in the flow space, in order to build up or decompose reactive species
Implementation Method 3
the liquid and the UV radiation are matched such that a majority of the UV radiation is absorbed in the liquid film in order to generate radicals in the liquid film
Implementation Method 4
Such hydroxyl radicals cause selective dissolution of organic materials from the substrate surface without harming metallic layers on the substrate surface if they are present
Data Source
AI summary
An apparatus for applying a liquid medium irradiated with UV radiation onto a substrate is disclosed, the apparatus comprising: a housing having an elongated chamber, at least one inlet opening, which opens into the chamber, and at least one slit shaped outlet opening opposite the inlet opening, which extends over the length of the chamber, a tube element, which extends in a longitudinal direction through the chamber, the tube element being at least partially transparent to UV radiation, wherein the tube element is arranged in the chamber such that a flow space is formed between the tube element and the wall of the chamber, the flow space being symmetric with respect to a longitudinal centre plane of the chamber, the longitudinal centre plane dissecting the outlet opening in its middle, and such that the tube element extends into the slit shaped outlet opening in the housing and thereby forms two longitudinally extending outlet slits between the tube element and the housing, and at least one UV-radiation source in the tube element, which is arranged to emit UV-radiation in the direction of the flow space and through the outlet opening out of the housing. The apparatus is distinguished by means for causing UV radiation to be emitted primarily in a first wavelength range through a first section of the tube member into the flow space and for causing UV radiation to be emitted primarily in a second wavelength range through a second section of the tube member through the outlet opening of the housing and optionally into an end region of the flow space adjacent to the outlet slits. The first and second wavelength ranges differ, and wherein for at least one of the sections, a maximum of 20%, preferably a maximum of 5%, of the radiation power emitted through the respective section comes from the other wavelength range.