Silicon-Containing Resist Patterning for High-Aspect Patterns
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Solution Overview
Problem
Existing patterning processes face challenges in forming fine patterns with high aspect ratios without pattern collapse, particularly in advanced lithography technologies like EUV and extreme ultraviolet ray lithography, due to issues such as acid diffusion, pattern deformation, and poor edge roughness.
Innovation Solution
A patterning process using a resist material containing a polymer with silicon-containing acid-labile groups, where the resist film is exposed, baked, and then developed by dry etching to form a pattern, leveraging the difference in etching rates between exposed and unexposed portions to prevent pattern collapse.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If chemically-amplified resist materials are used to enhance sensitivity and contrast, then sensitivity and contrast are improved, but acid diffusion occurs which degrades resolution
Solution Approach 1:
The patent introduces a quencher component that is distributed throughout the resist material to locally neutralize acid diffusion. This quencher selectively reacts with diffusing acid molecules, creating zones of high acid concentration only where needed for dissolution, thereby maintaining sensitivity while controlling resolution.
Solution Approach 2:
The patent employs a quencher as an intermediary substance between the acid generator and the substrate. This quencher mediates the acid diffusion process by temporarily binding with acid molecules, preventing direct acid diffusion that would degrade resolution, while still allowing controlled acid release for dissolution.
2Manufacturing precision
If post-exposure baking time and temperature are reduced to minimize acid diffusion, then resolution is improved, but sensitivity and contrast significantly decrease
Solution Approach 1:
The patent incorporates the acid generator and quencher components into the resist material structure before exposure. This preliminary arrangement ensures that the acid-generating capability and acid-quenching capability are pre-positioned throughout the resist, eliminating the need for extended post-exposure baking to control acid diffusion while maintaining adequate sensitivity.
Solution Approach 2:
The patent changes the chemical composition parameters of the resist material by incorporating specific acid-generating moieties and quencher molecules. This chemical parameter change allows the system to achieve controlled acid diffusion and dissolution at lower baking temperatures and shorter times, thereby improving resolution without sacrificing sensitivity.
3Manufacturing precision
If rinsing liquids with low surface tension are used to reduce stress during spin-drying, then pattern collapse is reduced, but the method is not sufficient for patterns with pitch of 20 nm or less
Solution Approach 1:
The patent replaces the mechanical approach of using low surface tension rinsing liquids with a chemical approach. The acid-labile group deprotection creates a chemically differentiated pattern that is etched selectively, eliminating the need for mechanical stress reduction through rinsing liquid modification and enabling smaller pattern dimensions.
Solution Approach 2:
The patent introduces an acid-labile group as an intermediary that mediates between the exposure process and the final pattern formation. This intermediary group is deprotected during exposure to create a soluble pattern, eliminating the need for stress-reducing rinsing liquids and enabling high-resolution patterning.
4Manufacturing precision
If exposed portions are opened by dry etching after shrinkage due to deprotection, then pattern formation is achieved, but large shrinkage causes deformation of two-dimensional patterns and triangular cross-sections
Solution Approach 1:
The patent changes the chemical parameter of the resist material by incorporating acid-labile groups that deprotect to create soluble patterns. This chemical parameter change enables direct dissolution-based patterning without mechanical shrinkage, maintaining accurate pattern geometry and aspect ratios while achieving effective pattern formation.
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
The process enables the formation of fine patterns with high aspect ratios without pattern collapse by utilizing the polymer's silicon-containing groups to control etching rates, reducing silicon content in exposed areas and forming positive patterns with enhanced selectivity.
Implementation Method 1
a polymer having a silicon-containing acid-labile group; subjecting the resist film to exposure and baking, and then to development by dry etching
Implementation Method 2
image blurs due to acid diffusion become a problem. To ensure resolution for fine patterns with dimensional sizes of 45 nm and smaller, there is a proposal that it is important to not only improve dissolution contrast as previously reported, but also control acid diffusion
Implementation Method 3
development by dry etching to form a pattern, leveraging the difference in etching rates between exposed and unexposed portions
Data Source
AI summary
The present invention is a patterning process including: providing a resist material containing a polymer having a silicon-containing acid-labile group; forming a resist film by using the resist material; and subjecting the resist film to exposure and baking, and then to development by dry etching to form a pattern. This can provide a patterning process according to which a fine pattern can be formed with a high aspect ratio and without pattern collapse occurring.