Block Copolymer Directed Self-Assembly for Sub-Resolution Patterning
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Solution Overview
Problem
Current methods for forming minute or reduced contact holes and patterns in semiconductor devices face limitations in resolution and complexity, particularly in photolithography processes, which struggle to achieve precise and repeatable patterns with small dimensions.
Innovation Solution
A method involving a hydrophilic guide layer, a developable bottom anti-reflective coating (DBARC) layer, and a block copolymer layer with microphase separation, where the block copolymer forms patterns through self-assembly, allowing for the formation of contact holes and line patterns with precise dimensions by etching the object layer using a pattern mask.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If photolithography process is used to form minute contact holes and patterns, then manufacturing capability is maintained, but manufacturing precision deteriorates due to resolution limits
Solution Approach 1:
The patent introduces a guide layer as an intermediary between the substrate and the block copolymer layer. This guide layer pattern serves as a template that directs the self-assembly of block copolymers, enabling the formation of minute contact holes with precision beyond conventional photolithography limits. The guide layer acts as a mediator that translates larger-scale photolithography patterns into finer-scale self-assembled structures.
Solution Approach 2:
The patent replaces the direct photolithography exposure process with a self-assembly mechanism. Instead of relying on light exposure to directly define the final pattern, the process uses spontaneous block copolymer self-organization guided by a template, substituting the optical-mechanical exposure system with a thermodynamic self-assembly system that achieves higher resolution.
2Manufacturing precision
If wavelength of light source is decreased to improve resolution, then manufacturing precision improves, but device complexity increases due to specialized equipment requirements
Solution Approach 1:
The patent changes the fundamental parameter of pattern formation from direct optical exposure to thermodynamic self-assembly. By transitioning from a light-based mechanism to a temperature-driven self-organization process, the method achieves higher resolution without requiring specialized high-energy light sources or complex optical systems.
Solution Approach 2:
The block copolymer system performs self-service by automatically organizing into the desired pattern through spontaneous self-assembly. The system uses its own internal thermodynamic driving forces to form the minute contact holes, eliminating the need for complex external equipment to force the pattern formation.
3Manufacturing precision
If effective aperture of lens is increased to improve resolution, then manufacturing precision improves, but device complexity increases due to optical system requirements
Solution Approach 1:
The patent substitutes the optical lens-based resolution enhancement mechanism with a self-assembly mechanism. Instead of increasing lens aperture to achieve finer resolution, the process uses the natural self-organizing behavior of block copolymers to create fine patterns, replacing complex optical mechanics with simpler thermodynamic self-organization.
4Manufacturing precision
If conventional photolithography is used for minute patterns, then process simplicity is maintained, but manufacturing precision deteriorates due to resolution limits
Solution Approach 1:
The patent segments the pattern formation process into two distinct stages: first forming a guide layer pattern using conventional photolithography, then using block copolymer self-assembly to create the final minute contact hole pattern. This segmentation allows each stage to operate at its optimal resolution level, with the guide layer providing the template and the self-assembly providing the fine-scale detail.
Solution Approach 2:
The guide layer serves as an intermediary that bridges the gap between conventional photolithography capabilities and the desired fine-scale patterns. It translates the larger-scale exposure pattern into a template that directs the formation of much finer contact holes through self-assembly, enabling precision beyond what either method could achieve alone.
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 contact holes and line patterns with reduced widths beyond the limits of conventional photolithography, achieving uniform and repeatable patterns with improved pattern density and reduced processing complexity.
Implementation Method 1
forming a pattern layer including first patterns and second patterns by microphase separating the block copolymer layer, each of the first patterns and each of the second patterns being repeatedly disposed
Implementation Method 2
forming a block copolymer layer on the neutral layer pattern and filling the first opening portions, the block copolymer layer including a block copolymer having a first polymer block and a second polymer block
Implementation Method 3
forming a hydrophilic guide layer on a substrate including an object layer formed thereon
Data Source
AI summary
A method includes forming a hydrophilic guide layer, a DBARC layer and a photoresist film. A portion of the photoresist film and DBARC layer is exposed to form exposed and unexposed portions. The unexposed photoresist film is removed to form a photoresist pattern including the exposed photoresist film portion. A neutral layer is formed on the photoresist pattern. The photoresist pattern and the DBARC layer of the exposed portion are removed to form first opening portions exposing the guide layer. A block copolymer layer includes a block copolymer having first and second polymer blocks coated on the neutral layer while filling the first opening portions. The block copolymer layer is microphase separated to form a pattern layer including first and second patterns. A pattern including one polymer block is removed to form a pattern mask. The object layer is etched to form a pattern including second opening portions.