EUV Patterning Process for High-Resolution Resist Patterns
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In fine processing using EUV exposure, pattern collapse is a challenge due to increased resolution, sensitivity, and aspect ratio, with previous chemically amplified resists having insufficient etching resistance, making thinning difficult.
Innovation Solution
A patterning process involving a substrate coated with a first resist material containing a thermosetting compound with protected hydroxy or carboxy groups, followed by EUV or electron beam exposure to deprotect these groups, and then applying a second resist material with a metal compound for crosslinking, forming a metal film pattern with improved sensitivity and resolution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If chemically amplified resist materials are used to enhance sensitivity and contrast through acid diffusion, then sensitivity and contrast are improved, but acid diffusion causes image blurring and reduced resolution for fine patterns
Solution Approach 1:
The patent changes the fundamental mechanism from acid-diffusion-based chemically amplified resists to direct photo-decomposition of the resist polymer itself. By using polymers with specific chemical structures (cyclic carbonates, cyclic carbamates, orthoesters, orthocarbonates) that undergo direct scission upon EUV exposure, the process eliminates acid diffusion while maintaining high sensitivity and achieving superior resolution for sub-10nm patterning
Solution Approach 2:
The invention extracts and removes the acid generator component from the resist system entirely. By designing resists that rely on direct photodecomposition of the polymer backbone without requiring acid catalysts, the patent eliminates the harmful acid diffusion effect while preserving the necessary sensitivity for EUV lithography
2Manufacturing precision
If non-chemically amplified resist materials like PMMA are used to avoid acid diffusion, then resolution is improved, but etching resistance is reduced due to lack of cyclic structure
Solution Approach 1:
The patent creates composite molecular structures within the resist polymer that combine the benefits of both linear and cyclic structures. The resist contains repeating units with cyclic structures (cyclic carbonates, cyclic carbamates, orthoesters, orthocarbonates) embedded in the polymer chain, providing etching resistance while the overall linear polymer structure maintains processability and resolution
3Manufacturing precision
If resist thickness is reduced to prevent pattern collapse during miniaturization, then resolution is improved, but etching resistance and processability are worsened
Solution Approach 1:
The patent changes the chemical composition and molecular structure of the resist material to achieve superior etching resistance at reduced thicknesses. By incorporating highly crosslinkable cyclic structures and using EUV-sensitive polymers with high absorption coefficients, the resist maintains adequate mechanical strength and etching resistance even at ultra-thin dimensions required for sub-10nm patterning
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 achieves a thin film resist pattern with higher sensitivity and resolution, along with excellent etching resistance and storage stability, suitable for very large-scale integration (LSI) and EUV exposure applications.
Implementation Method 1
adding an acid generator that generates a bulky acid
Implementation Method 2
turns insoluble in alkaline developer through crosslinking by condensation reaction of silanol generated by EUV irradiation
Implementation Method 3
increases solubility in organic solvent developer through scission of the main chain by EUV irradiation
Data Source
AI summary
A patterning process, including steps of: forming the first resist film from the first resist material containing a thermosetting compound having a hydroxy group and/or a carboxy group each protected by an acid-labile group, an acid generator, and a sensitizer; irradiating the first resist film with a high energy beam or an electron beam to perform pattern exposure to deprotect the hydroxy group and/or carboxy group in a pattern exposed portion; forming the second resist film from second resist material containing (A) metal compound on the first resist film, and forming a crosslinked portion wherein the component (A) and deprotected hydroxy group and/or deprotected carboxy group are crosslinked on the pattern exposed portion; and developing the second resist film with a developer to give a metal film pattern composed of the crosslinked portion. This provides a method for forming a thin film resist pattern with higher resolution and higher sensitivity.