Novolac Resist Underlayer Composition for Etching and Heat Resistance
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Solution Overview
Problem
Existing resist underlayer films in semiconductor processing lack sufficient etching resistance, heat resistance, curing properties, and pattern embedding properties, necessitating improvements to meet the demands of advanced semiconductor manufacturing processes.
Innovation Solution
A resist underlayer film-forming composition comprising a novolac resin with specific unit structures and organic groups, optionally including a crosslinking agent, solvent, and other additives, which enhances heat resistance, etching resistance, and curing properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional polymers with indole derivatives or diarylaminobenzyl alcohol derivatives are used, then etching resistance is improved, but heat resistance and curing properties are insufficient
Solution Approach 1:
The patent uses a composite material system consisting of a novolac resin backbone with fused ring structures (providing heat resistance) combined with specific end cap groups containing aromatic rings (providing etching resistance). This composite structure achieves both high heat resistance and high etching resistance simultaneously, resolving the contradiction between these two properties.
Solution Approach 2:
The patent changes the chemical structure parameters of the resin by introducing specific fused ring structures (naphthalene, anthracene, phenanthrene) and controlling the end cap groups with aromatic rings. These structural parameter changes enable the material to achieve both high heat resistance (through fused ring stability) and high etching resistance (through aromatic ring density), resolving the contradiction between heat resistance and etching resistance.
2Strength
If polymer structures with high etching resistance are used, then etching resistance is improved, but film uniformity and pattern embedding properties deteriorate
Solution Approach 1:
The patent applies local quality by having different structural features at different parts of the polymer molecule: the fused ring structure in the backbone provides local heat resistance, while the aromatic end cap groups provide local etching resistance. This localized functional distribution allows the material to achieve high etching resistance without compromising film uniformity, resolving the contradiction between etching resistance and film uniformity.
3Strength
If existing resist underlayer film materials are used, then etching resistance is improved, but curing properties and pattern embedding properties are insufficient
Solution Approach 1:
The patent creates a composite molecular structure where the novolac resin backbone with fused rings provides thermal stability for curing, while the aromatic end cap groups provide etching resistance. This composite structure achieves both high etching resistance and excellent curing properties, resolving the contradiction between these two requirements.
Data Source
AI summary
[Problem] The purpose of the present invention is to provide a resist underlayer film-forming composition in which properties of a resist underlayer film, such as curing properties, heat resistance, etching resistance, planarization properties and embedding properties are further improved. [Solution] A resist underlayer film-forming composition comprising a novolac resin and a solvent, wherein the novolac resin includes a unit structure A having at least two amino groups, the unit structure A being a divalent group derived from a compound having a fused ring structure, and further includes a monovalent organic group C1 or organic group C2 that caps at least one end of the novolac resin.