Resist Underlayer Film Composition for Stepped Substrate Planarization
Solution Overview
Problem
Resist underlayer film-forming compositions struggle with poor coatability on stepped substrates, resulting in films with large variations in thickness and unevenness, which complicates the miniaturization of resist patterns in semiconductor manufacturing.
Innovation Solution
A resist underlayer film-forming composition incorporating a polymer with a specific aromatic group structure, a solvent with a boiling point of 160°C or above, and optional crosslinking agents, acids, or acid generators, which forms a flat film with high etching resistance and suitable optical constants.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional resist underlayer film-forming compositions are applied to stepped substrates to achieve high etching resistance, then etching resistance is improved, but coatability deteriorates resulting in large variations in film thickness
Solution Approach 1:
The patent changes the chemical composition parameters of the polymer by introducing specific aromatic groups (naphthyl, anthracenyl, or pyrenyl structures) into the polymer chain. This compositional modification enables the film-forming composition to achieve both high etching resistance and good coatability on stepped substrates, resolving the contradiction between etching resistance and film thickness uniformity
Solution Approach 2:
The patent creates a composite polymer structure combining aromatic groups with specific side chain structures. This composite material approach allows the resist underlayer film to simultaneously exhibit high etching resistance from the aromatic core structure and good flow properties for uniform coating on stepped substrates from the side chain architecture
2Manufacturing precision
If resist underlayer films are formed to support miniaturization of resist patterns, then pattern resolution is improved, but substrate complexity increases due to stepped structures
Solution Approach 1:
The patent applies the resist underlayer film-forming composition to the stepped substrate before forming the final resist pattern. This preliminary action allows the composition to flow and fill the stepped structures, creating a planarized surface that simplifies subsequent lithography processes and enables better pattern miniaturization
Solution Approach 2:
The patent modifies the polymer composition parameters to achieve optimal viscosity and film-forming properties that allow the composition to adequately fill and planarize stepped substrate structures, thereby reducing the effective complexity of the substrate for subsequent processing steps
Data Source
AI summary
A composition for forming a resist underlayer film exhibits strong etching resistance, has a good dry etching rate ratio and a good optical constant, and is capable of forming a film that provides good coverage over a so-called multilevel substrate and that is flat with reduced difference in thickness after embedding. A resist underlayer film uses said composition for forming a resist underlayer film; and a method for producing a semiconductor device. The composition for forming a resist underlayer film contains: a polymer having the partial structure represented by formula (1); and a solvent. (In the formula, Ar represents an optionally substituted C6-20 aromatic group.)