Silicon-Containing Resist Underlayer Film Composition
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In the context of miniaturized semiconductor manufacturing, the challenge lies in forming ultrafine patterns without pattern collapse and achieving high etching selectivity in multilayer resist methods, where current silicon-containing resist underlayer films fail to provide sufficient adhesiveness and etching resistance, leading to defects and substrate damage.
Innovation Solution
A composition for forming a silicon-containing resist underlayer film is developed, comprising a compound with an isocyanuric acid structure and a thermally crosslinkable polysiloxane, along with an acid generator, which enhances adhesiveness and etching selectivity, preventing pattern collapse and enabling precise pattern transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the thickness of the photoresist film is reduced to accommodate pattern miniaturization, then the resolution improves, but the etching resistance decreases and pattern collapse occurs
Solution Approach 1:
The patent divides the single photoresist film into a multilayer structure consisting of an upper photoresist layer and a lower silicon-containing underlayer. This segmentation allows each layer to perform its specialized function: the upper layer provides patterning resolution while the lower layer provides etching resistance, thereby resolving the contradiction between achieving fine pattern resolution and maintaining sufficient etching resistance.
Solution Approach 2:
The patent employs a composite material system where the lower underlayer combines silicon-containing compounds with specific organic resins (novolak, polyhydroxystyrene, or aliphatic polycyclic resins) to create a material that simultaneously achieves high etching resistance against fluorine-based plasma and appropriate adhesion to the upper photoresist layer, while the upper layer uses resins optimized for resolution at shorter wavelengths.
2Reliability
If a silicon-containing resist underlayer film is used to improve etching resistance, then the etching selectivity improves, but the adhesiveness to the photoresist film deteriorates
Solution Approach 1:
The patent carefully controls the silicon content in the underlayer within the range of 0.1-10 mass% and adjusts the molecular weight and chemical structure of the organic resin components to optimize both etching selectivity and adhesion. By parameterizing the composition rather than using fixed formulations, the patent achieves a balance where the silicon provides sufficient etching resistance while the organic resin matrix maintains appropriate adhesion properties.
Solution Approach 2:
The underlayer is designed as a composite material combining silicon-containing compounds (for etching resistance) with organic resins (for adhesion). The composite structure allows the silicon component to provide the necessary selectivity against fluorine-based plasma while the organic resin component ensures proper bonding to the upper photoresist layer, thereby resolving the contradiction between these two opposing requirements.
3Manufacturing precision
If the photoresist film thickness is reduced for miniaturization, then the pattern resolution improves, but the aspect ratio increases causing pattern collapse
Solution Approach 1:
By segmenting the resist system into upper and lower layers with distinct thicknesses and functions, the patent enables the upper layer to be optimized for resolution (thinner) while the lower layer provides structural support (thicker), thereby maintaining pattern stability and preventing collapse during the etching process.
Solution Approach 2:
The multilayer composite structure provides differential mechanical and chemical properties: the upper photoresist layer offers high resolution and appropriate solubility for patterning, while the lower silicon-containing layer provides enhanced mechanical strength and etching resistance, collectively preventing pattern collapse that would occur with a single thin layer.
4Manufacturing precision
If resins with low absorption at exposure wavelength are used to enhance resolution, then the manufacturing precision improves, but the etching resistance decreases
Solution Approach 1:
The patent assigns different functional roles to different layers: the upper photoresist layer uses resins (novolak, polyhydroxystyrene, or aliphatic polycyclic) optimized for low absorption at the exposure wavelength to achieve high resolution, while the lower silicon-containing underlayer is specifically designed to provide the etching resistance that the upper layer sacrifices for resolution.
Solution Approach 2:
The patent creates a composite resist system where the upper layer materials are selected for optimal optical properties (low absorption at i-line, KrF, or ArF wavelengths) to achieve high resolution, while the lower silicon-containing layer compensates for the reduced etching resistance by providing a protective underlayer with high etching selectivity, thereby allowing each material to be optimized for its primary function.
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 proposed composition effectively suppresses pattern collapse, ensures high etching selectivity, and facilitates the transfer of precise patterns to the substrate, improving the yield and reliability of semiconductor device manufacturing.
Implementation Method 1
a thermally crosslinkable polysiloxane
Implementation Method 2
the remaining silicon-containing resist underlayer film is removed generally by dry etching with fluorine-based gas plasma or wet etching with, for example, alkali- or fluorine-based etching solution
Implementation Method 3
a compound shown by the following general formula (A-1)
Implementation Method 4
the resist upper layer film pattern can be transferred to the silicon-containing resist underlayer film by dry etching with fluorine-based gas plasma
Implementation Method 5
dry etching with fluorine-based gas plasma
Implementation Method 6
A material and a process reliably employed in this patterning process are urgently needed
Data Source
AI summary
A composition for forming a silicon-containing resist underlayer film contains a compound shown by the following general formula (A-1) and a thermally crosslinkable polysiloxane. R1 represents a methyl group, an ethyl group, a propyl group, an allyl group, or a propargyl group. R2 represents a hydrogen atom, an acetyl group, an acryloyl group, a methacryloyl group, a benzoyl group, a naphthoyl group, or an anthranoyl group. R3 represents a methyl group, an ethyl group, a propyl group, an allyl group, a propargyl group, or a group shown by the following general formula (A-2), where a broken line represents a bonding arm, and R1 and R2 are as defined above. An object of the present invention is to provide a silicon-containing resist underlayer film capable of exhibiting high effect of suppressing ultrafine pattern collapse and forming a resist pattern with favorable pattern profile in multilayer resist methods.