Crosslinked Random Copolymer Neutral Layers for Directed Self-Assembly
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Solution Overview
Problem
Conventional lithographic techniques face limitations in achieving smaller pattern dimensions due to aberrations, focus issues, and wavelength constraints, making it difficult to further reduce feature sizes in microelectronic devices, while directed self-assembly of block copolymers offers potential for enhanced resolution but requires effective neutral or pinning layers for proper alignment and pattern transfer.
Innovation Solution
Development of novel crosslinked random copolymer compositions that can form either neutral or pinning layers on semiconductor, metal, and metal oxide substrates through spin coating and post-bake, allowing for improved alignment and pattern multiplication in directed self-assembly processes, specifically using acrylate or methacrylate repeat units with pendant benzocyclobutene, which maintain their properties during processing and enhance lithographic performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional lithographic techniques are used to expose photoresist, then manufacturing process is simple and well-established, but pattern dimension resolution is limited due to aberrations, focus constraints, and wavelength limitations
Solution Approach 1:
A neutral layer is introduced as an intermediary between the substrate and the block copolymer. This neutral layer mediates the interaction by providing a surface that does not preferentially interact with either block of the copolymer, enabling proper self-assembly and alignment of the microdomains during the directed self-assembly process, thereby achieving higher resolution patterns without excessive process complexity
Solution Approach 2:
The patent uses composite material systems including block copolymers with distinct etch-resistant and etch-labile blocks, combined with neutral layer compositions containing specific functional groups. This composite approach enables the system to achieve nanoscale resolution by leveraging the self-assembly properties of block copolymers while the neutral layer provides the necessary interface control
2Manufacturing precision
If directed self-assembly of block copolymers is implemented to enhance resolution, then pattern multiplication and higher resolution are achieved, but proper alignment requires complex neutral or pinning layers
Solution Approach 1:
The neutral layer composition is designed with specific local chemical properties (functional groups such as carboxylic acid, hydroxyl, or amine groups at controlled concentrations) that create the appropriate local interaction environment for block copolymer self-assembly. This localized chemical functionality enables precise alignment control without requiring complex overall layer structures
Solution Approach 2:
The patent controls the concentration and type of functional groups in the neutral layer (e.g., carboxylic acid groups at 1-10 mmol/g) to optimize the interaction strength with block copolymer blocks. By adjusting these parameters, the neutral layer provides the right balance of interaction to enable alignment while maintaining structural simplicity
3Reliability
If neutral layer compositions are optimized for block copolymer alignment, then self-assembly performance improves, but the layer must maintain stability during subsequent processing steps
Solution Approach 1:
The neutral layer is designed with functional groups that are pre-configured to provide the necessary interaction with block copolymer blocks before self-assembly occurs. The layer is applied and stabilized with appropriate functional group concentrations (e.g., 1-10 mmol/g carboxylic acid groups) in advance, ensuring both processing stability and proper copolymer interaction during subsequent steps
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 novel compositions enable higher resolution and better pattern uniformity in microelectronic devices by allowing precise alignment and etching of block copolymer domains, reducing processing steps and improving pattern multiplication, thus overcoming the limitations of conventional lithography.
Implementation Method 1
novel methods for using the neutral layer or pinning layer compositions for aligning microdomains of directed self-assembling block copolymers (BCP)
Implementation Method 2
novel crosslinked random copolymer compositions that can form either neutral or pinning layers on semiconductor, metal, and metal oxide substrates through spin coating and post-bake
Implementation Method 3
The directed self-assembly block copolymer comprises a block of etch resistant copolymeric unit and a block of highly etchable copolymeric unit, which when coated, aligned and etched on a substrate give regions of very high density patterns
Data Source
AI summary
The present invention relates to a composition comprises at least one random copolymer having at least one repeat unit of structure (1), The present invention also relates to novel processes for forming patterns using this novel crosslinked layer on a substrate by enable a film of a block copolymer coated on the novel crosslinked layer to undergo self-assembly.