Metal-Containing EUV Resist Post-Treatment for Etch Selectivity
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Solution Overview
Problem
Current EUV photoresist processing techniques face challenges in achieving high etch selectivity and line edge roughness, particularly in advanced technology nodes where sub-30 nm features are required, due to limitations in wet development methods and suboptimal dry development selectivity.
Innovation Solution
The method involves post-application and post-exposure treatments of EUV photoresists using thermal processes and remote plasma to modify material properties, controlling temperature, gas ambient, and pressure, which increases etch selectivity and reduces line edge roughness by enhancing the contrast between exposed and unexposed regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If wet development methods are used, then the photoresist can be developed, but etch selectivity is insufficient for sub-30 nm features
Solution Approach 1:
The patent applies parameter changes by modifying the photoresist material composition to include metal and metal oxide components, which fundamentally alter the material's interaction with etch gases. This compositional parameter change enables superior etch selectivity compared to conventional organic photoresists, allowing sub-30 nm feature fabrication with adequate process window.
2Manufacturing precision
If conventional photoresist formulations are used, then the process is simple, but line edge roughness is high
Solution Approach 1:
The patent employs composite materials by formulating the photoresist as a composite system containing metal particles, metal oxides, and organic binder materials. This composite structure provides multiple beneficial effects: the metal/metal oxide components enhance etch selectivity and reduce line edge roughness through controlled material properties, while the organic matrix maintains film integrity and processability.
3Manufacturing precision
If higher EUV radiation doses are used, then line edge roughness decreases, but dose to size increases
Solution Approach 1:
The patent utilizes parameter changes in the photoresist's physical and chemical properties through metal and metal oxide incorporation. These material parameter changes result in enhanced EUV absorption characteristics and modified post-exposure behavior, enabling lower dose-to-size values while maintaining low line edge roughness through the unique etching properties of the metal-containing formulation.
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 improves dry development performance by achieving higher etch selectivity and critical dimension consistency with lower EUV radiation doses, reducing line edge roughness and line width roughness, and enabling more aggressive processing conditions without delamination or interface failures.
Implementation Method 1
the treatment may involve a thermal process with control of temperature, pressure, ambient gas chemistry, gas flow/ratio, and moisture
Implementation Method 2
the treatment may be a post-application remote plasma treatment
Implementation Method 3
a remote plasma treatment that generates radicals that react with the photoresist to modify one or more material properties of the photoresist
Data Source
AI summary
Various embodiments described herein relate to methods, apparatus, and systems for treating metal-containing photoresist to modify material properties of the photoresist. For instance, the techniques herein may involve providing a substrate in a process chamber, where the substrate includes a photoresist layer over a substrate layer, and where the photoresist includes metal, and treating the photoresist to modify material properties of the photoresist such that etch selectivity in a subsequent post-exposure dry development process is increased. In various embodiments, the treatment may involve exposing the substrate to elevated temperatures and/or to a remote plasma. One or more process conditions such as temperature, pressure, ambient gas chemistry, gas flow/ratio, and moisture may be controlled during treatment to tune the material properties as desired.