Radiation Sensitive Self-Assembled Monolayers for Sub-100 nm Lithography
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Solution Overview
Problem
Current lithographic resist technologies face challenges in achieving sub-100 nm feature resolution due to limitations in etch resistance, line edge roughness, and depth of focus, particularly with the use of traditional phenolic resins and aliphatic polymers, which are not sufficient for deep UV exposure and dry etching techniques.
Innovation Solution
Development of radiation-sensitive compounds with a surface binding group, a metal binding group, and a radiation-sensitive group that self-assemble into monolayers on substrates, allowing for UV or e-beam radiation activation to improve etch resistance and pattern definition, enabling the formation of ultra-thin, high-resolution resist films.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If traditional phenolic resins are used for lithographic resists, then etch resistance is improved, but absorption at wavelengths below 200 nm increases
Solution Approach 1:
The patent changes the chemical composition parameters of the resist material by using aliphatic and cycloaliphatic polymers instead of phenolic resins. These alternative polymers have different chemical structures that reduce absorption at deep UV wavelengths (below 200 nm) while maintaining sufficient etch resistance for the fabrication process.
2Object-affected harmful factors
If aliphatic polymers are used as resist films for deep UV exposure, then absorption at deep UV wavelengths is reduced, but etch resistance decreases
Solution Approach 1:
The patent creates a composite material system by combining aliphatic or cycloaliphatic polymers with metal species (such as aluminum, zinc, or magnesium). The polymer provides good deep UV transmission properties while the metal species contributes etch resistance, creating a composite that achieves both requirements simultaneously.
3Strength
If resist thickness is increased to compensate for poor etch performance, then etch resistance is improved, but aspect ratio control becomes difficult
Solution Approach 1:
The patent changes the material properties of the resist film by incorporating metal species into the polymer matrix. This modification improves the etch resistance of the film itself, allowing thin films (reducing the thickness parameter) to achieve sufficient etch protection without increasing the aspect ratio, thereby maintaining manufacturing precision.
4Manufacturing precision
If very thin resist films are used to maintain aspect ratio, then line collapse is reduced, but etch resistance becomes insufficient
Solution Approach 1:
The patent employs composite materials consisting of aliphatic or cycloaliphatic polymers combined with metal species. The polymer component enables the use of very thin film structures that prevent line collapse, while the metal species embedded in the composite provides the necessary etch resistance, allowing thin films to serve both purposes simultaneously.
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 use of these compounds allows for the creation of ultra-thin self-assembled films with enhanced etch resistance and reduced line edge roughness, minimizing depth of focus issues and enabling precise patterning of sub-100 nm features, suitable for advanced lithographic applications.
Implementation Method 1
The radiation sensitive group is displaced from the compound upon exposure to UV or e-beam radiation, thereby activating the metal binding group to interact with a metal species
Implementation Method 2
organic molecules containing certain terminal head groups will self assemble from solution to form monolayers on specific surfaces
Implementation Method 3
The monolayers are stabilized by the chemisorption of the head group to the surface and the formation of covalent bonds
Data Source
AI summary
The invention is directed to a radiation sensitive compound comprising a surface binding group proximate to one end of the compound for attachment to a substrate, and a metal binding group proximate to an opposite end of the compound. The metal binding group is not radiation sensitive. The radiation sensitive compound also includes a body portion disposed between the surface binding group and the metal binding group, and a radiation sensitive group positioned in the body portion or adjacent to the metal binding group. The surface binding group is capable of attaching to a substrate selected from a metal, a metal oxide, or a semiconductor material.