Block Copolymer Pattern Transfer via Selective Fluorocarbon Etching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods face challenges in achieving selective etching of block copolymers with similar chemical compositions, particularly when both polymer segments contain similar structures, leading to difficulties in distinguishing and removing specific segments during the nano-lithography process.
Innovation Solution
The method involves using a reaction gas containing fluorocarbon and oxygen, with a flow rate ratio of fluorocarbon to oxygen between 0.5 and 7.5, to selectively etch one polymer segment of a block copolymer, allowing the remaining segment to form a microstructure on a substrate, which can then be used as an etching mask for patterned substrate preparation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional etching processes are used on block copolymers with similar chemical compositions, then the etching process can be performed, but etching selectivity is insufficient and it becomes difficult to selectively remove specific polymer segments
Solution Approach 1:
The patent changes the chemical composition parameters of the etching gas from conventional oxygen-based gases to a specific mixture containing fluorocarbon (20-80 sccm) and oxygen (20-80 sccm) with flow rate ratios between 0.5 and 7.5. This parameter change enables selective etching of block copolymers with similar chemical compositions by exploiting differential reactivity to fluorocarbon-containing plasma, achieving etching selectivity where conventional methods failed.
2Manufacturing precision
If the block copolymer contains segments with similar structures, then the material composition can be optimized for self-assembly, but it becomes difficult to distinguish and selectively etch specific segments
Solution Approach 1:
The patent introduces fluorocarbon-containing etching gas as an intermediary that mediates the differentiation between similar polymer segments. The fluorocarbon components react differently with the two polymer segments even when they have similar structures, creating sufficient contrast in etching rates. This intermediary enables precise pattern formation by allowing selective removal of one segment while preserving the other, solving the segment differentiation problem.
3Reliability
If the etching gas composition is optimized for selectivity, then selective etching of one segment can be achieved, but the etching process becomes more complex to control
Solution Approach 1:
The patent establishes specific parameter ranges for fluorocarbon flow rate (20-80 sccm), oxygen flow rate (20-80 sccm), and their ratio (0.5-7.5) to achieve selective etching. By defining these concrete parameter boundaries, the patent simplifies process control while maintaining high selectivity. The parameter optimization ensures that within these ranges, selective etching is reliably achieved without requiring complex real-time adjustments.
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 efficient and accurate transfer of self-assembled block copolymer patterns onto substrates, allowing for the formation of patterned substrates with nano-scale precision by selectively etching one segment while preserving the other for masking.
Implementation Method 1
a step of selectively etching any one segment block of the block copolymer, wherein the etching is performed using a reaction gas containing fluorocarbon and oxygen
Implementation Method 2
The block copolymer can form a periodically arranged structure such as a sphere, a cylinder or a lamella by phase separation
Implementation Method 3
The domain shape and size of the structure formed by a self-assembly phenomenon of the block copolymer can be extensively controlled
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The present application relates to a method for preparing a patterned substrate. According to the method of the present application, in a process of transferring a self-assembled pattern of a block copolymer on a substrate to form a pattern, the self-assembled pattern of the block copolymer can be efficiently and accurately transferred on the substrate to prepare a patterned substrate.