Spin-On Carbon Underlayer for Thin Photoresist Pattern Transfer
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Solution Overview
Problem
Thin photoresist films lack sufficient etch resistance and adhesion to substrates, leading to delamination during processing, and current CVD methods for carbon hardmasks are inefficient and expensive.
Innovation Solution
A spin-on carbon (SOC) composition is developed, comprising specific compounds and polymers with aromatic groups, divalent linkers, and solvents, which can be applied as a photoresist underlayer to enhance adhesion and planarization, suitable for use in semiconductor manufacturing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If thin photoresist films are used for miniaturization, then imaging capability is improved, but etch resistance deteriorates
Solution Approach 1:
The patent introduces an SOC underlayer as an intermediary between the photoresist and substrate. This underlayer serves as a mediator that provides the necessary etch resistance and adhesion, allowing the thin photoresist to maintain its imaging capability while the system as a whole achieves sufficient pattern transfer fidelity through the underlayer's protective function
Solution Approach 2:
The SOC underlayer is formed as a composite material system comprising aromatic compounds with specific functional groups (hydroxyl, carboxyl, amino groups) combined with divalent linkers. This composite structure provides both the adhesion needed to prevent delamination and the etch resistance required for pattern transfer, while maintaining compatibility with thin photoresist films
2Strength
If CVD method is used to produce carbon hardmask, then etch resistance is improved, but manufacturing efficiency deteriorates
Solution Approach 1:
The patent replaces the CVD (chemical vapor deposition) process with a spin-coating process to form the SOC underlayer. This substitution transitions from a complex, time-consuming, and expensive CVD method to a simpler, faster, and more cost-effective solution that achieves comparable or superior etch resistance and adhesion properties
Solution Approach 2:
The invention changes the fundamental parameters of the underlayer formation process by using solution-processable aromatic compounds that can be deposited via spin-coating. The aromatic compounds with specific functional groups (Y1, Y2) and divalent linkers (X1, X2, X3) provide the necessary film properties through chemical structure design rather than complex deposition parameters, enabling rapid and efficient manufacturing
3Strength
If SOC composition is used to improve adhesion, then delamination is prevented, but material selection complexity increases
Solution Approach 1:
The patent applies local quality by introducing specific functional groups (Y1 and Y2) at particular positions on the aromatic compounds. These functional groups (hydroxyl, carboxyl, amino groups) are strategically placed to provide adhesion at the substrate interface, while the rest of the molecular structure maintains the desired film properties. This localized functional group placement achieves superior adhesion without requiring complex overall material compositions
Solution Approach 2:
The invention simplifies material selection by defining specific molecular structure parameters: aromatic compounds with 1-3 aromatic rings, specific functional groups (Y1, Y2) at defined positions, and divalent linkers (X1, X2, X3) with controlled lengths. These parameter specifications provide a clear framework for selecting materials that automatically achieve good adhesion and etch resistance, reducing the complexity of material selection while ensuring performance
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 SOC composition provides improved etch resistance, adhesion, and planarization, enabling successful pattern transfer and protecting substrates from damage during processing steps.
Implementation Method 1
should be capable of being cast onto a substrate by a spin-coating process
Implementation Method 2
should be thermally set upon heating with low out-gassing and sublimation
Data Source
AI summary
A method of forming a pattern, the method comprising: providing a photoresist underlayer over a substrate; forming a photoresist layer over the photoresist underlayer; patterning the photoresist layer; and transferring a pattern from the patterned photoresist layer to the photoresist underlayer;wherein the photoresist underlayer is formed from a composition comprising a solvent and a compound represented by Formula 1ora polymer having a repeating unit represented by Formula 2wherein in Formulae 1 and 2:Ar1 and Ar2 independently represent an aromatic group; andY1, Y2, X1, X2, X3, T1, T2, Z1, and Z2 are as defined.