EUV Light Generation Apparatus with Hydrogen Radical Debris Etching
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Solution Overview
Problem
Current EUV light generation systems face challenges in producing extreme ultraviolet light with feature sizes of 32 nm or less, requiring advanced systems for generating EUV light at a wavelength of approximately 13 nm, and suffer from performance degradation due to target material debris deposition on optical elements.
Innovation Solution
The system includes a chamber with a target supply unit, a discharge pump, optical elements, and a temperature control mechanism, utilizing a two-stage laser irradiation process to generate EUV light and employing hydrogen radicals to etch Sn debris from optical elements, maintaining optimal temperature ranges to prevent redeposition and enhance etching efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a laser produced plasma system is used to generate EUV light, then EUV light can be produced for microfabrication, but target material debris deposits on optical elements causing performance degradation
Solution Approach 1:
The patent introduces hydrogen radicals that react with deposited tin debris on optical elements to form volatile stannane gas, which is then removed by vacuum pumps. This converts the harmful deposition process into a beneficial in-situ cleaning mechanism, maintaining optical element performance without interrupting EUV light generation
Solution Approach 2:
Hydrogen radicals serve as an intermediary substance that mediates between the deposited tin debris and the removal process. The hydrogen radicals diffuse to the optical element surfaces, react with tin to form stannane, and enable indirect removal of debris through chemical transformation rather than direct mechanical or thermal cleaning
2Productivity
If hydrogen radicals are introduced to etch Sn debris, then cleaning efficiency improves, but temperature control becomes critical to prevent redeposition
Solution Approach 1:
The patent precisely controls the temperature of optical elements within a specific range (20°C to 150°C, preferably 40°C to 100°C) to optimize the balance between etching efficiency and redeposition prevention. By maintaining this temperature window, the system ensures that stannane removal dominates while suppressing tin vaporization and redeposition, achieving effective cleaning without requiring extreme temperature conditions
Solution Approach 2:
The system incorporates temperature sensors and control mechanisms that continuously monitor and adjust optical element temperatures. This feedback loop ensures temperatures remain within the optimal range for hydrogen radical etching while preventing conditions that would cause redeposition, automatically adapting to maintain cleaning efficiency
3Manufacturing precision
If the chamber is maintained at high vacuum for EUV generation, then light quality improves, but debris deposition accelerates due to enhanced vapor transport
Solution Approach 1:
The patent exploits the high vacuum conditions that normally accelerate debris transport by introducing hydrogen radicals that chemically transform deposited tin into volatile stannane. The same vacuum environment that facilitates rapid deposition also enables efficient stannane removal, converting the harmful deposition mechanism into a beneficial self-cleaning process
Solution Approach 2:
Hydrogen radicals act as a reactive species analogous to a strong oxidant, rapidly reacting with deposited tin to form stannane gas. This chemical reaction accelerates the removal process, ensuring that debris is converted and evacuated faster than it can accumulate, even under high vacuum conditions that enhance vapor transport
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 configuration effectively generates EUV light for microfabrication with feature sizes of 32 nm or less, reduces performance degradation by efficiently etching Sn debris from optical elements, and maintains optimal temperature control to prevent redeposition, ensuring reliable operation.
Implementation Method 1
a Laser Produced Plasma (LPP) type system in which plasma is generated by irradiating a target material with a laser beam
Implementation Method 2
plasma is generated by irradiating a target material with a laser beam
Implementation Method 3
a discharge pump connected to the chamber
Implementation Method 4
a collector mirror for collecting the extreme ultraviolet light emitted from plasma of the target material
Implementation Method 5
at least one temperature control mechanism for controlling a temperature of the at least one optical element
Implementation Method 6
employing hydrogen radicals to etch Sn debris from optical elements
Data Source
AI summary
An apparatus for generating extreme ultraviolet light used with a laser apparatus and connected to an external device so as to supply the extreme ultraviolet light thereto includes a chamber provided with at least one inlet through which a laser beam is introduced into the chamber; a target supply unit provided on the chamber configured to supply a target material to a predetermined region inside the chamber; a discharge pump connected to the chamber; at least one optical element provided inside the chamber; an etching gas introduction, unit provided on the chamber through which an etching gas passes; and at least one temperature control mechanism for controlling a temperature of the at least one optical element.