Neutral Orientation Layer for Block Copolymer Lithography
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for forming graphoepitaxy and chemical epitaxy templates for self-assembled block copolymers in lithography face challenges such as material compatibility issues, contamination risks, and limited substrate-polymer interactions, which affect resolution and process complexity.
Innovation Solution
A method involving selective exposure of a resist layer to actinic radiation, followed by developer removal to create resist features, and application of a neutral orientation layer bonded between these features, allowing the neutral layer to be unbonded and easily removed, thereby facilitating the formation of a patterned neutral orientation layer for guiding self-assembly of block copolymers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional imprint lithography methods are used, then pattern transfer can be achieved, but resolution is limited by the emission wavelength of radiation source or numerical aperture of projection system
Solution Approach 1:
The patent introduces self-assembled block copolymer layers as intermediary structures that enable pattern formation beyond the limits of direct photolithography. The block copolymers self-assemble into ordered domains that serve as nanoscale templates, allowing resolution to be determined by polymer domain size rather than optical system limitations.
Solution Approach 2:
The patent changes the fundamental parameter determining resolution from optical system characteristics (wavelength, numerical aperture) to polymer physical parameters (domain size, spacing). By controlling block copolymer composition, molecular weight, and self-assembly conditions, resolution can be tuned independently of lithography equipment capabilities.
2Measurement precision
If self-assembled block copolymers are used for high resolution patterning, then resolution can be improved beyond prior art methods, but material compatibility issues and contamination risks arise
Solution Approach 1:
The patent introduces orientation control layers as intermediary structures between the substrate and self-assembled block copolymers. These orientation control layers provide chemically inert, compatible surfaces that guide polymer self-assembly while preventing direct unwanted interactions between the polymer and substrate, thereby reducing contamination and compatibility issues.
Solution Approach 2:
The patent applies different surface properties to different regions through the orientation control layer, creating locally optimized interfaces. The orientation control layer provides specific chemical and physical properties that are locally tailored to promote uniform block copolymer self-assembly while preventing contamination at the polymer-substrate interface.
3Manufacturing precision
If complex steps like thermal reflow or lift-off are used in template formation, then pattern alignment can be achieved, but process complexity increases
Solution Approach 1:
The orientation control layer serves as a mediator that simplifies the patterning process by providing pre-defined alignment features. Instead of requiring complex thermal reflow or lift-off steps, the orientation control layer directly guides block copolymer self-assembly into aligned patterns through its structured surface properties.
Solution Approach 2:
The patent performs preliminary patterning of the orientation control layer before block copolymer deposition. This preliminary action creates pre-defined alignment features and domains that guide subsequent self-assembly, eliminating the need for complex post-deposition alignment steps like thermal reflow or lift-off.
4Device complexity
If direct deposition of self-assembled polymer layers is performed, then process complexity can be reduced, but alignment and ordering of domains may be insufficient
Solution Approach 1:
The orientation control layer acts as an intermediary that enables direct deposition of block copolymers while ensuring proper alignment and ordering. The orientation control layer provides structured surface properties that guide self-assembly into well-ordered domains with correct alignment, eliminating the need for complex post-processing steps.
Solution Approach 2:
The orientation control layer provides locally optimized surface properties that promote uniform and ordered self-assembly. By creating regions with specific chemical and physical characteristics, the orientation control layer ensures that block copolymers self-assemble into well-aligned patterns directly upon deposition, without requiring additional complexity.
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 approach enhances the resolution and reduces process complexity by allowing direct deposition of self-assembled polymer layers on substrates, improving the alignment and ordering of domains, and eliminating the need for complex steps like thermal reflow or lift-off, thus enabling high-resolution lithography.
Implementation Method 1
selectively exposing a resist layer to actinic radiation to provide exposed and unexposed regions of resist layer
Implementation Method 2
the unbonded neutral orientation layer is removed from the resist features by application of a vacuum or by rinsing with an organic solvent
Implementation Method 3
they may undergo an order-disorder transition on cooling below a certain temperature (order-disorder transition temperature To/d) resulting in phase separation of copolymer blocks
Data Source
AI summary
A method is disclosed involving depositing a neutral orientation template layer onto a substrate after formation of chemical epitaxy or graphoepitaxy features on the substrate, but before deposition and orientation of a self-assemblable polymer. The orientation layer is arranged to bond with the substrate but not with certain features, so that it may be easily removed by vacuum or rinsing with organic solvent. The neutral orientation layer has a chemical affinity to match that of blocks in the self-assemblable polymer so that blocks of differing types wet the neutral orientation layer so that domains in the self-assembled polymer may lie side by side along the substrate surface, with interfaces normal to the substrate surface. The resulting aligned and oriented self-assembled polymer may itself be used as a resist for device lithography of the substrate.