EUV Patterning Process for High-Resolution Metal Film Resist
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In fine processing using EUV exposure, pattern collapse occurs due to increased resolution, sensitivity, and aspect ratio, with previous chemically amplified resists having insufficient etching resistance, making thin film formation challenging.
Innovation Solution
A patterning process involving a substrate coated with a first resist material containing an acid generator and a thermosetting compound with protected hydroxy or carboxy groups, followed by baking, then a second resist material with a metal compound and sensitizer, exposed to EUV or electron beams to deprotect and crosslink, enabling the formation of 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 blurs and reduces resolution for fine patterns
Solution Approach 1:
The patent changes the fundamental mechanism from chemically amplified (acid diffusion-based) to non-chemically amplified resist materials. This parameter change eliminates acid diffusion while maintaining sensitivity through alternative mechanisms such as direct EUV photon absorption and molecular scission, thereby resolving the contradiction between sensitivity enhancement and resolution maintenance
Solution Approach 2:
The invention extracts and removes the acid generator component from the resist system entirely. By eliminating the acid diffusion mechanism while retaining the essential resist functions through direct photolysis and molecular weight reduction, the patent resolves the conflict between sensitivity (achieved through acid diffusion in conventional systems) and resolution (degraded by acid diffusion blurs)
2Manufacturing precision
If PMMA is used as a non-chemically amplified resist material to avoid acid diffusion, then resolution is improved, but etching resistance is reduced due to lack of cyclic structure
Solution Approach 1:
The patent employs composite resist materials that combine the resolution advantages of linear chain polymers (like PMMA) with the etching resistance of cyclic structures. The composite formulation integrates molecules containing cyclic moieties (such as cyclopentene or norbornene rings) into the polymer backbone or as side groups, thereby simultaneously achieving high resolution and adequate etching resistance
Solution Approach 2:
The invention introduces cyclic structures locally within specific regions or segments of the polymer chain rather than requiring the entire polymer to have cyclic structure. This local quality approach allows the resist to maintain the solubility and resolution characteristics of linear chains while gaining etching resistance from localized cyclic moieties
3Stability of the object's composition
If resist film thickness is reduced to prevent pattern collapse in miniaturization, then pattern stability is improved, but etching resistance and subsequent etching process performance are degraded
Solution Approach 1:
The patent changes the material composition parameters of the resist film to achieve enhanced etching resistance per unit thickness. By incorporating high-Z elements, crosslinkable functional groups, or molecules with high etching selectivity, the resist maintains adequate etching protection even at reduced thicknesses required for pattern stability in miniaturized structures
4Manufacturing precision
If metal atoms are incorporated into resist materials to improve sensitivity and resolution, then patterning performance is enhanced, but metal transfer to substrate causes semiconductor malfunction
Solution Approach 1:
The patent introduces an intermediary barrier layer between the metal-containing resist and the substrate. This intermediate layer prevents metal atom transfer to the substrate while allowing the metal-enhanced patterning performance to be maintained. The intermediary acts as a protective interface that blocks harmful metal migration during subsequent processing steps
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 LSI production and EUV exposure applications.
Implementation Method 1
containing an acid generator and a thermosetting compound having a hydroxy group and/or a carboxy group each protected by an acid-labile group
Implementation Method 2
a crosslinked portion in which the component (A) and the deprotected hydroxy group and/or the deprotected carboxy group are crosslinked
Implementation Method 3
irradiating the first resist film and the second resist film with a high energy beam from a light source of an extreme ultraviolet ray with a wavelength of 3 to 15 nm or an electron beam
Data Source
AI summary
A patterning process, including: forming the first resist film from first resist material containing an acid generator and thermosetting compound having a hydroxy group and/or carboxy group protected by an acid-labile group; forming the second resist film on first resist film from a second resist material containing a metal compound (A) and a sensitizer; irradiating the first and second 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 of first resist film and to form a crosslinked portion of the component (A) with the deprotected hydroxy and/or carboxy group 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.