Silicon Cyclic Underlayer Composition for Lithography Etching

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Solution Overview

Problem

Current resist underlayer film compositions for semiconductor lithography fail to achieve a high dry etching rate and anti-reflective coating functionality while preventing intermixing with resist films, especially with the increasing use of shorter wavelength light sources in semiconductor production.

Innovation Solution

A resist underlayer film forming composition incorporating hydrolyzable organosilanes with cyclic organic groups containing carbon, nitrogen, and heteroatoms, which form a polyorganosiloxane structure upon hydrolysis and condensation, acting as both a hardmask and anti-reflective coating, and utilizing specific etching gases to enhance dry etching rates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a hardmask containing metal element such as silicon is used as underlayer film, then reflection preventing effect is achieved, but removal rate by dry etching decreases and film thickness of photoresist decreases significantly

Engineering Contradiction:

Improvereflection preventing effectVSAvoidfilm thickness of photoresist

Core Design Contradiction:

Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The invention changes the chemical composition parameters of the underlayer film by incorporating specific silicon compounds with cyclic organic groups containing heteroatoms (oxygen, nitrogen, or sulfur). This compositional modification enables the underlayer film to achieve both high dry etching resistance and controlled removal characteristics, while maintaining anti-reflective properties without significantly reducing photoresist film thickness

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention uses composite materials consisting of silicon compounds combined with cyclic organic groups (such as oxazolidinone, isoxazolidinone, thiazolidinone rings). This composite structure provides both the metal element content needed for reflection prevention and the organic component that controls etching behavior, achieving a balance between hardmask functionality and photoresist protection

Inventive Principle:

Principle #40Composite materials

2Manufacturing precision

If shorter wavelength active rays are used for lithography, then fine processing capability is improved, but reflection from substrate becomes a larger issue

Engineering Contradiction:

Improvefine processing capabilityVSAvoidreflection from substrate

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The invention introduces an intermediary underlayer film composed of silicon compounds with cyclic organic groups between the substrate and photoresist. This intermediary layer serves dual functions: it prevents reflection of shorter wavelength active rays from the substrate while also providing controlled etching characteristics that protect the photoresist during processing

Inventive Principle:

Principle #24Intermediary (Mediator)

3Adaptability or versatility

If underlayer film serves as both hardmask and anti-reflective coating, then functionality is improved, but intermixing with resist occurs

Engineering Contradiction:

Improvefunctionality as hardmask and anti-reflective coatingVSAvoidintermixing with resist

Core Design Contradiction:

Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The invention applies local quality by designing the underlayer film with specific silicon compounds containing cyclic organic groups that create distinct chemical zones. The film structure provides regions with different etching rates and chemical compositions, enabling it to function as both hardmask and anti-reflective coating while maintaining compositional stability and preventing intermixing with the resist layer

Inventive Principle:

Principle #3Local quality

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 allows for the formation of fine rectangular patterns on semiconductor substrates, preventing pattern collapse and ensuring high dry etching resistance, thus enabling efficient semiconductor device production with improved pattern fidelity and reduced resist film thickness.

Implementation Method 1

comprising: as a silane: at least one among a hydrolyzable organosilane, a hydrolysis product thereof, and a hydrolysis-condensation product thereof

Methodology Applied

Scientific EffectHydrolysis: Hydrolysis

Implementation Method 2

a hydrolysis-condensation product thereof, in which the silane includes a silane having a cyclic organic group

Methodology Applied

Scientific EffectCondensation: Condensation

Data Source

PatentUS10079146B2Resist underlayer film forming composition containing silicon containing cyclic organic group having hetero atom

Publication Date: 2018.09.18 NISSAN CHEM CORP

AI summary

A resist underlayer film composition for lithography, including: a silane: at least one among a hydrolyzable organosilane, a hydrolysis product thereof, and a hydrolysis-condensation product thereof, wherein the silane includes a silane having a cyclic organic group containing as atoms making up the ring, a carbon atom, a nitrogen atom, and a hetero atom other than a carbon and nitrogen atoms. The hydrolyzable organosilane may be a hydrolyzable organosilane of Formula (1), wherein, at least one group among R1, R2, and R3 is a group wherein a —Si(X)3 group bonds to C1-10 alkylene group, and other group(s) among R1, R2, and R3 is(are) a hydrogen atom, C1-10 alkyl group, or C6-40 aryl group; a cyclic organic group of 5-10 membered ring containing atoms making up the ring, a carbon atom, at least one of nitrogen, sulfur or oxygen atoms; and X is an alkoxy group, acyloxy group, or halogen atom.