Underlayer Film Composition for Directed Self-Assembly Lithography
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Solution Overview
Problem
Conventional underlayer films for directed self-assembly lithography processes face challenges in achieving uniform surface free energy and high alignment orientation with few defects, particularly in forming fine patterns required for miniaturized electronic devices.
Innovation Solution
A composition comprising a polymer with a specific partial structure represented by formula (1) and a solvent is used to form an underlayer film, which enables phase separation and superior alignment orientation through directed self-assembly, improving defect performance and film uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional underlayer films are used for directed self-assembly lithography, then phase separation can be achieved, but uniform surface free energy and high alignment orientation with few defects cannot be achieved
Solution Approach 1:
The invention changes the chemical composition parameters of the underlayer film by using a random copolymer with specific monomer ratios (styrene 30-70 mol%, methyl methacrylate 30-70 mol%). This parameter optimization achieves uniform surface free energy (40-50 mN/m) and reduces defects, resolving the contradiction between alignment quality and pattern precision
Solution Approach 2:
The invention creates a composite underlayer film system by combining random copolymer with specific molecular weight range (1,000-50,000) and controlled composition. This composite approach enables simultaneous achievement of good adhesion, uniform surface properties, and high alignment orientation with few defects
2Manufacturing precision
If block copolymer is used for directed self-assembly, then fine patterns can be formed, but clustering of polymer structures occurs during annealing
Solution Approach 1:
The random copolymer underlayer film acts as an intermediary layer between the substrate and the block copolymer directed self-assembled film. This intermediary underlayer with optimized surface free energy prevents polymer structure clustering during annealing while enabling fine pattern formation, resolving the contradiction between pattern fineness and structural uniformity
3Ease of manufacture
If underlayer film surface free energy is not controlled, then film formation is simple, but phase separation structure quality deteriorates
Solution Approach 1:
The invention establishes specific parameter ranges for the underlayer film: random copolymer composition (styrene 30-70 mol%, methyl methacrylate 30-70 mol%), molecular weight (1,000-50,000), and surface free energy (40-50 mN/m). Within these parameters, the film can be formed using conventional simple processes while achieving high-quality phase separation structures with good alignment and few defects
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 described composition and process result in an underlayer film with enhanced alignment orientation and reduced defects, facilitating the formation of high-quality phase separation structures for advanced lithography applications, such as in semiconductor and liquid crystal devices.
Implementation Method 1
a lithography process which utilizes a phase separation structure by so-called directed self-assembly that spontaneously forms an ordered pattern
Data Source
AI summary
A composition includes a polymer (1) having a partial structure represented by formula (1), and a solvent. X is a hydrogen atom, a halogen atom, a hydroxyl group, an alkyl group having 1 to 5 carbon atoms, a hydroxyalkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Y is a monovalent organic group having 1 to 12 carbon atoms and containing a hetero atom or a monovalent inorganic acid group. Z is a linking group represented by —O—, —S—, or —NR—, where R is an organic group having 1 to 20 carbon atoms. R1 and R2 are each independently a hydrogen atom, a halogen atom, or an organic group having 1 to 20 carbon atoms, or the like.