Silicon Resist Underlayer Composition for Sub-25 Nm Pattern Stability
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Solution Overview
Problem
Existing semiconductor production processes face challenges in forming stable resist patterns with high aspect ratios due to pattern collapse and deterioration during ultrafine patterning, particularly in EUV lithography, where the half pitch is less than 25 nm, and current materials are expensive and difficult to obtain.
Innovation Solution
A silicon-containing resist underlayer film-forming composition comprising polysiloxane with an ester structure and a solvent, which includes specific siloxane unit structures and hydrolysis condensates, is used to form a resist underlayer film that prevents pattern collapse and supports high lithographic properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If silane compounds with special functional groups (e.g., norbornene ring) are used to improve lithographic properties, then pattern stability is improved, but manufacturing cost increases and material availability decreases
Solution Approach 1:
The patent replaces expensive, difficult-to-obtain silane compounds with special functional groups (like norbornene rings) with conventional, readily available silane compounds. The invention achieves comparable pattern stability using common materials such as tetraethyl orthosilicate (TEOS) or methyl trimethoxysilane, making the material economically viable and easily manufacturable without requiring specialized chemical synthesis.
Solution Approach 2:
The patent modifies the chemical composition parameters of the resist underlayer film by incorporating specific ratios of silicon-containing compounds (5-50 mass%) and adjusting the molecular structure through controlled hydrolysis and condensation reactions. This parameter optimization enables conventional silane compounds to achieve lithographic performance previously only attainable with expensive specialized compounds.
2Reliability
If silane compounds with special functional groups are used to improve lithographic properties, then pattern stability is improved, but production cost increases
Solution Approach 1:
The patent substitutes expensive specialized silane compounds with conventional, commercially available silane materials. By using standard chemicals like TEOS, methyl trimethoxysilane, or ethyl trimethoxysilane that can be purchased off-the-shelf, the production cost is dramatically reduced while maintaining the necessary pattern stability for ultrafine lithography.
Solution Approach 2:
The patent optimizes the concentration and molecular weight parameters of silicon-containing compounds in the resist underlayer composition. By controlling the silicon content at 5-50 mass% and adjusting the hydrolysis-condensation degree, the formulation achieves cost-effective performance using inexpensive bulk chemicals rather than expensive specialized compounds.
3Manufacturing precision
If resist thickness is reduced to achieve miniaturization, then resolution is improved, but pattern collapse increases
Solution Approach 1:
The patent creates a composite resist underlayer system combining an organic underlayer film with a silicon-containing resist underlayer film. This composite structure provides mechanical support to prevent pattern collapse while maintaining the thin profile needed for high resolution. The silicon-containing layer forms a crosslinked network that reinforces the overall pattern stability.
Solution Approach 2:
The patent applies the resist underlayer film formation process before the main resist coating. This preliminary action creates a supportive foundation layer that prevents pattern collapse during subsequent processing steps. The underlayer is formed by spin-coating and baking the silane composition, creating a pre-stabilized surface that supports ultrafine pattern formation.
4Quantity of substance
If conventional resist underlayer films are used, then production cost is reduced, but lithographic properties deteriorate
Solution Approach 1:
The patent transforms conventional silane compounds into high-performance lithographic materials by optimizing key parameters: silicon content (5-50 mass%), solvent composition (mixing ratios of water, alcohol, and non-aqueous solvents), and processing conditions (baking temperature and time). These parameter adjustments enable ordinary silane compounds to achieve the lithographic precision previously reserved for specialized expensive materials.
Solution Approach 2:
The patent creates a composite formulation combining silicon-containing compounds with specific solvents and additives. This composite approach enhances the lithographic properties of conventional materials by improving film uniformity, adhesion, and crosslinking characteristics, achieving high-resolution patterning capability using cost-effective material combinations.
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 composition enables the formation of stable resist patterns without collapse, even at resolutions below 25 nm, while reducing production costs and enhancing lithographic performance in semiconductor manufacturing.
Implementation Method 1
a siloxane unit structure having an ester structure... a hydrolysis condensate
Implementation Method 2
a siloxane unit structure having an ester structure... a hydrolysis condensate
Data Source
AI summary
A silicon-containing resist underlayer film-forming composition for forming a silicon-containing resist underlayer film that enables the formation of a good resist pattern causing no pattern collapse even in ultra-fine patterning at a resolution (hp) of less than 25 nm, the composition comprising: [A] a polysiloxane containing a siloxane unit structure having an ester structure; and [B] a solvent.