UV-Assisted Resist Underlayer for EUV Lithography
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Solution Overview
Problem
In EUV lithography, the integrity of the EUV resist pattern is poor due to the low etch resistance of EUV resists, leading to pattern collapse and challenges in achieving desired resolution and aspect ratios.
Innovation Solution
A method for forming a resist underlayer with increased photoresist adhesion using a UV-assisted deposition process, where a resist underlayer agent comprising a chemical compound with specific hydrocarbon functional groups is exposed to the substrate to deposit an ultrathin single molecular underlayer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If EUV lithography is used to scale down feature sizes, then resolution is improved, but etch resistance deteriorates leading to pattern collapse
Solution Approach 1:
The patent introduces a resist underlayer as an intermediary between the substrate and the EUV photoresist. This underlayer serves as a mediator that provides mechanical support and etch resistance to the thin photoresist layer, enabling the formation of high-resolution features without pattern collapse during etching processes.
Solution Approach 2:
The patent employs a composite structure consisting of multiple material layers: a substrate, a resist underlayer with specific chemical composition (containing aromatic rings and heteroatoms), and an EUV photoresist layer. This composite material system combines the high resolution capability of EUV lithography with the enhanced etch resistance provided by the specially designed underlayer.
2Manufacturing precision
If photoresist layer is made thinner to achieve desired aspect ratio, then manufacturing precision is improved, but etch resistance deteriorates
Solution Approach 1:
The resist underlayer acts as a mediator that compensates for the reduced thickness of the photoresist layer. By providing a supportive foundation with high etch resistance, the underlayer enables the use of thinner photoresist layers to achieve desired aspect ratios while preventing pattern collapse during etching.
Solution Approach 2:
The patent modifies the chemical parameters of the underlayer material, specifically incorporating aromatic rings and heteroatoms to enhance etch resistance. This parameter change in material composition allows the underlayer to provide sufficient mechanical and chemical support for thin photoresist layers with high aspect ratios.
3Strength
If conventional photoresist is used, then etch resistance is maintained, but sensitivity to EUV wavelength deteriorates
Solution Approach 1:
The patent segments the resist system into two distinct functional layers: a resist underlayer optimized for etch resistance and mechanical support, and an EUV photoresist layer optimized for sensitivity to EUV wavelength. This segmentation allows each layer to be independently optimized for its specific function, achieving both high etch resistance and high EUV sensitivity 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 method improves adhesion between the resist underlayer and the EUV photoresist, reducing the risk of pattern collapse and enhancing the ability to form thinner, high-resolution layers with improved etch resistance.
Implementation Method 1
exposing the substrate to UV radiation in an atmosphere of a resist underlayer agent to deposit the resist underlayer
Implementation Method 2
deposit the resist underlayer over a top surface of the substrate
Implementation Method 3
exposing the substrate to a resist underlayer agent to deposit the resist underlayer
Data Source
AI summary
The present disclosure generally relate to the field of semiconductor processing and, in particular, to methods of forming a resist underlayer for use in EUV lithography processing. In some embodiments, the present disclosure provides a method for forming a resist underlayer having improved adhesion using a resist underlayer agent. In some embodiments, the resist underlayer is formed using the resist underlayer agent in a UV-assisted deposition process.