Block Copolymer Self-Assembly for Fine Semiconductor Patterns
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Solution Overview
Problem
Current semiconductor manufacturing techniques, such as photolithographic processes and Resist Enhancement Lithography Assisted by Chemical Shrink (RELACS), face limitations in achieving high integration density due to restricted pattern resolution, non-uniformity in pattern formation, and material costs, which hinder the production of fine patterns and increase fabrication costs.
Innovation Solution
A method involving the formation of a block copolymer with hydrophobic and hydrophilic radicals on a semiconductor substrate, where the copolymer self-assembles into a pillar or line pattern, allowing for selective removal of the hydrophobic radical to create uniformly spaced, fine contact holes or line patterns, using a hydrophilic polymer as a mask for etching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If photolithographic process with short-wavelength light source is used, then pattern resolution is improved, but fabrication cost increases and integration density is still limited
Solution Approach 1:
The patent introduces block copolymer as an intermediary material that self-assembles to form patterns. The block copolymer acts as a mediator between the photoresist pattern and the final etched pattern, enabling sub-lithographic resolution without requiring expensive shorter-wavelength light sources. The hydrophobic and hydrophilic blocks self-organize into periodic structures that define the final pattern dimensions.
Solution Approach 2:
The block copolymer performs self-assembly to automatically form the desired pattern structure. The hydrophobic and hydrophilic blocks spontaneously organize into periodic domains through thermodynamic self-organization, eliminating the need for complex lithographic equipment and expensive materials. This self-service mechanism achieves high-resolution patterning at lower cost.
2Length of moving object
If photoresist reflow process is used to reduce contact hole pattern size, then pattern dimension is reduced, but pattern uniformity deteriorates
Solution Approach 1:
The block copolymer introduces local quality differences through its hydrophobic and hydrophilic blocks, which self-assemble into periodic structures with distinct local properties. This creates uniform local environments throughout the pattern, ensuring consistent etching behavior and uniform pattern dimensions across the entire structure, unlike the non-uniform photoresist reflow process.
Solution Approach 2:
The patent changes the physical and chemical parameters of the patterning system by using block copolymer self-assembly instead of photoresist reflow. The block copolymer's phase separation temperature, block ratio, and molecular weight are controlled to achieve desired pattern dimensions with superior uniformity, providing a new parameter space for pattern formation.
3Manufacturing precision
If RELACS process is used to form fine pattern, then pattern fineness is improved, but material cost increases and development residue remains
Solution Approach 1:
The block copolymer serves as a temporary, disposable patterning layer that is selectively removed after serving its purpose. This disposable approach uses inexpensive materials compared to RELACS, and the block copolymer is completely removed without leaving residues, eliminating the need for expensive materials while achieving fine pattern formation.
Solution Approach 2:
The patent changes the material parameters by using block copolymer with controlled block ratios and molecular weights to achieve fine pattern formation. This alternative material system provides comparable or superior pattern fineness to RELACS while being significantly cheaper and leaving no development residues.
4Productivity
If photolithographic process is used, then pattern formation is achieved, but integration density is limited due to resolution restrictions
Solution Approach 1:
The patent transitions from two-dimensional photolithographic patterning to three-dimensional block copolymer self-assembly. The block copolymer forms vertical pillar structures that provide additional dimensional control, enabling sub-lithographic resolution and higher integration density by exploiting the third dimension for pattern definition.
Solution Approach 2:
The block copolymer segments into distinct hydrophobic and hydrophilic domains that self-organize into periodic structures. This segmentation creates multiple resolvable features from a single lithographic pattern, effectively multiplying the pattern density and enabling higher integration without requiring proportionally smaller lithographic features.
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 enables the formation of uniformly spaced, fine patterns with improved integration density and reduced fabrication costs by overcoming the limitations of existing technologies, enhancing the yield and reliability of semiconductor devices.
Implementation Method 1
assembling the block copolymer to allow the polymer having the hydrophobic radical to be formed in a pillar pattern within the polymer having the hydrophilic radical
Data Source
AI summary
A method of manufacturing a semiconductor device is provided. According to an embodiment, the method includes forming a layer to be etched on a semiconductor substrate, and forming a photoresist pattern on the layer to be etched. A block copolymer including a hydrophobic radical and a hydrophilic radical is formed in the photoresist pattern, and the block copolymer is assembled to allow a polymer having the hydrophobic radical to be formed in a pillar pattern within a polymer having the hydrophilic radical. The polymer having the hydrophobic radical is then selectively removed.