Conductive Coating for EUV Patterning Device Contaminant Suppression
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Solution Overview
Problem
Extreme ultraviolet (EUV) radiation in lithographic apparatuses generates plasma, leading to contaminant particle release and defectivity, which disrupts pattern projection and increases maintenance needs, due to interactions with gas and surfaces within the apparatus.
Innovation Solution
A conductive coating with a high recombination coefficient is applied to dielectric components in the patterning device environment, suppressing EUV plasma-induced contaminant release and atomic hydrogen flux, combined with a gas inlet providing a low concentration of gases like O2, H2O2, or NO2 to convert radicals into less reactive molecules.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If EUV radiation power is increased to improve patterning capability, then manufacturing precision is improved, but contaminant particle release increases due to enhanced plasma generation
Solution Approach 1:
The patent converts the harmful EUV radiation that generates plasma and releases contaminants into a beneficial effect by using the same EUV radiation to actively clean the patterning device surface. A cleaning system exposes the patterning device to EUV radiation in controlled pulses, using the generated plasma to desorb and remove accumulated contaminant particles, thus transforming the harmful plasma effect into a self-cleaning mechanism that maintains patterning capability without continuous contamination buildup
Solution Approach 2:
The patent implements a periodic cleaning cycle where contaminant particles accumulated on the patterning device during normal operation are removed through controlled EUV exposure. The system discards the contaminated state by using EUV-induced plasma to eject particles, then recovers the patterning device's optimal performance by returning it to a clean state, enabling sustained high-precision manufacturing without permanent degradation from contamination
2Reliability
If conductive coating is applied to suppress contaminant release, then reliability is improved, but device complexity increases due to additional coating layers
Solution Approach 1:
The patent makes the patterning device surface multi-functional by applying a conductive coating that simultaneously serves two purposes: during normal operation, it suppresses contaminant particle release by dissipating electrostatic charges that would otherwise hold particles; during cleaning cycles, it facilitates EUV-induced plasma generation and charge dissipation to enable effective particle removal. This single coating layer performs both protective and active cleaning functions, improving reliability without proportionally increasing complexity
Solution Approach 2:
The patent employs a composite coating structure combining conductive materials (such as metal layers or conductive oxides) with adherent base layers on the patterning device substrate. This composite approach provides both the electrostatic charge dissipation needed for contaminant suppression and the adhesion required for durable, long-term operation. The layered composite structure achieves reliable contaminant management while maintaining manufacturing feasibility and controlling overall device complexity
3Manufacturing precision
If gas inlet with O2/H2O2/NO2 is introduced to convert radicals, then purity is improved, but device complexity increases due to additional gas delivery system
Solution Approach 1:
The patent introduces reactive gases (O2, H2O2, or NO2) through a gas inlet system that acts as an intermediary to convert harmful atomic hydrogen radicals into less reactive molecular forms. These gases are delivered in controlled amounts to react with H* radicals, converting them into H2O or other stable molecules that do not cause defectivity. This intermediary chemical conversion process protects the patterning device and substrate from radical-induced damage, improving manufacturing precision while using a relatively simple gas delivery mechanism
4Manufacturing precision
If cleaning frequency is increased to maintain pattern quality, then manufacturing precision is improved, but productivity decreases due to more maintenance activity
Solution Approach 1:
The patent implements continuous or near-continuous cleaning action by integrating EUV-induced plasma cleaning into the normal operational cycle. Rather than stopping production for separate cleaning operations, the system uses brief EUV exposure pulses during or between patterning operations to continuously remove contaminants. This maintains pattern quality throughout extended production runs without requiring frequent maintenance interruptions, thereby preserving both manufacturing precision and productivity
Solution Approach 2:
The patterning device performs its own cleaning function by utilizing EUV radiation exposure to generate plasma that actively removes contaminant particles from its surface. The conductive coating enhances this self-cleaning capability by facilitating charge dissipation and plasma generation. This self-service mechanism eliminates the need for external manual cleaning operations, allowing the device to maintain its own pattern quality automatically during production, thus improving precision without sacrificing throughput
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 conductive coating significantly reduces particle release and defectivity by enhancing recombination of atomic hydrogen and ions, while the gas inlet efficiently converts radicals, thereby improving the cleanliness and reliability of the patterning process.
Implementation Method 1
conductive coatings, that remove fluctuations of local (near particle) charge and/or charge density due to very high mobility of electrons within the coating
Implementation Method 2
suppressing atomic hydrogen (H*) flux and concentration to the most contaminated areas
Implementation Method 3
the EUV radiation may interact with matter present in the lithographic apparatus (e.g. small amounts of gas) to form a plasma
Implementation Method 4
EUV radiation may contribute to the generation of contamination within the lithographic apparatus
Implementation Method 5
a gas inlet providing a low concentration of gases like O2, H2O2, or NO2 to convert radicals into less reactive molecules
Data Source
AI summary
A component for use in a patterning device environment including a patterning device, wherein the component is treated to suppress EUV plasma-induced contaminant release and/or atomic hydrogen or other radicals induced defectivity. A conduit array comprising at least one conduit, wherein the at least one conduit has been treated to promote adhesion of a contaminant to the at least one conduit.