Resist Composition Water Repellency Immersion Lithography
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
ArF immersion lithography faces issues such as resist component leaching and water penetration due to acid generation and basic compound interactions, leading to pattern profile changes and defects, and existing protective coatings have environmental and cost concerns.
Innovation Solution
A resist composition comprising a copolymer of alkali-soluble (α-trifluoromethyl)acrylate and norbornene derivative, combined with a lactone ring or hydroxyl group-containing polymer, an acid generator, and an organic solvent, which forms a resist film with improved water repellency and slip, preventing leaching and penetration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If ArF immersion lithography is used to achieve higher resolution and smaller pattern rules, then manufacturing precision is improved, but resist components leach out and water penetrates into the resist film causing pattern defects
Solution Approach 1:
A protective coating layer is introduced as an intermediary between the resist film and water. This coating prevents water from penetrating into the resist film and stops resist components from leaching out, thereby maintaining pattern profile integrity while enabling ArF immersion lithography to achieve higher resolution
Solution Approach 2:
A thin protective coating film is applied over the resist film to create a barrier against water. This thin film structure maintains the fine pattern dimensions while providing protection against water penetration and component leaching, resolving the contradiction between achieving small pattern rules and maintaining pattern reliability
2Reliability
If a protective coating is applied to prevent resist component leaching and water penetration, then pattern profile reliability is improved, but process complexity and cost increase due to additional coating and stripping steps
Solution Approach 1:
The protective coating is combined with the resist formulation itself, creating an integrated system where the resist contains both the patterning functionality and the protective properties. This merging eliminates separate coating and stripping steps, reducing process complexity while maintaining pattern profile reliability
Solution Approach 2:
The resist composition is designed to perform multiple functions simultaneously: it provides patterning capability, water repellency, and protection against component leaching. This multi-functionality eliminates the need for separate protective coating steps, reducing process complexity while maintaining reliability
3Object-affected harmful factors
If fluorinated compounds are used for protective coating to achieve water repellency, then water repellency is improved, but environmental harm and cost increase due to use of fluorocarbon solvents
Solution Approach 1:
The chemical composition parameters of the resist are modified by incorporating specific polymers with inherent water repellency properties. This parameter change achieves the desired water repellency effect while using environmentally friendly, non-fluorinated materials, eliminating the environmental harm associated with fluorocarbon solvents
4Manufacturing precision
If water is used as immersion medium to increase NA and improve resolution, then manufacturing precision is improved, but acid generated from photoacid generator leaches out causing pattern defects
Solution Approach 1:
The protective coating acts as an intermediary barrier that prevents acid generated from the photoacid generator from leaching out into the water. This intermediary layer maintains the acid within the resist film, preserving pattern integrity while allowing water to function as the immersion medium for high-resolution imaging
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 resist composition enhances water repellency and slip, reducing development defects and maintaining pattern profile integrity, while being economically advantageous and environmentally friendly.
Implementation Method 1
a resist composition which has improved water repellency and water slip
Implementation Method 2
the copolymer of an alkali-soluble (α-trifluoromethyl)acrylate and a norbornene derivative
Implementation Method 3
preventing leaching and penetration
Implementation Method 4
water droplets remaining on the resist film, though in a minute volume, can penetrate into the resist film
Implementation Method 5
a compound capable of generating an acid upon exposure to high-energy radiation
Data Source
AI summary
A copolymer of an alkali-soluble (α-trifluoromethyl)-acrylate and a norbornene derivative is useful as an additive to a resist composition. When processed by immersion lithography, the resist composition exhibits excellent water repellency and water slip and forms a pattern with few development defects.