Block Copolymer Self-Assembly for Sub-Nanometer Patterning
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Solution Overview
Problem
Current semiconductor manufacturing processes face limitations in achieving finer patterning due to constraints in reducing the wavelength of light sources and increasing the numerical aperture of lenses, making it difficult to improve resolution without expensive extreme ultraviolet (EUV) exposure processes.
Innovation Solution
A method involving the formation of a neutral layer with an uneven structure, followed by coating a block copolymer layer that phase-separates into first and second patterns, allowing for etching processes using these patterns as masks, thereby overcoming the limitations of conventional exposure processes without requiring EUV technology.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the wavelength of the light source is reduced to improve resolution, then the resolution R is lowered, but the exposure process becomes more complex and expensive requiring EUV technology
Solution Approach 1:
The patent segments the patterning process into multiple steps: first forming a mandrel pattern, then using it as a template for block copolymer self-assembly, and finally transferring the pattern. This multi-stage approach allows achieving finer resolution without requiring a single high-complexity EUV exposure step.
Solution Approach 2:
The patent introduces a neutral layer as an intermediary between the mandrel pattern and the block copolymer layer. This neutral layer mediates the interaction by providing a controlled interface that enables uniform block copolymer self-assembly, thereby achieving precise pattern transfer without direct complex EUV processing of the final pattern.
2Manufacturing precision
If the numerical aperture NA of the lens is increased to improve resolution, then the resolution R is lowered, but the lens design and manufacturing become more difficult
Solution Approach 1:
The patent employs block copolymers that perform self-assembly to form the final fine pattern. The block copolymer molecules autonomously organize into desired structures (cylinders, lamellae, or gyroids) based on their inherent phase separation properties, eliminating the need for complex high-NA lens systems to force the pattern formation.
Solution Approach 2:
The patent changes the fundamental parameter from optical resolution (dependent on wavelength and numerical aperture) to self-organized structural periodicity (dependent on block copolymer composition and processing conditions). By controlling parameters such as block copolymer ratio, molecular weight, and annealing conditions, fine patterns are achieved without requiring high-NA lenses.
3Device complexity
If conventional photolithography is used to maintain process simplicity, then the exposure process remains simple, but the achievable pattern size is limited
Solution Approach 1:
The patent performs preliminary actions by first forming a mandrel pattern using conventional photolithography, then using this mandrel as a template to guide the subsequent block copolymer self-assembly. This preliminary structuring enables the final pattern to achieve dimensions smaller than what conventional photolithography alone could produce, while still starting from a simple process.
Solution Approach 2:
The patent implements a nested structure where the block copolymer pattern is formed within and guided by the mandrel pattern. The mandrel serves as an outer template, and the block copolymer forms an inner fine pattern, creating a nested hierarchical structure that combines the simplicity of conventional lithography with the fineness of self-assembly.
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 method enables the formation of patterns with sizes smaller than those achievable by conventional photolithography, reducing production costs and improving resolution without the need for expensive EUV equipment.
Implementation Method 1
phase-separating the block copolymer layer to form a plurality of first patterns spaced apart from each other and a second pattern filling a space between the first patterns
Data Source
AI summary
The inventive concepts provide methods of forming a pattern. In the method, a block copolymer layer may be formed on a neutral layer having an uneven structure and then phase separation is induced. The neutral layer may have an affinity for all of a hydrophilic polymer and a hydrophobic polymer, so that vertical cultivation of phases of the block copolymer may be realized on the uneven structure. Thus, a self-assembled phenomenon may be induced.