Thin Film Intermediary for Block Copolymer Resist Pattern Stability

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Solution Overview

Problem

The existing methods for forming fine resist patterns using block copolymers often result in deformation of the resist pattern during heat treatment, leading to undesired shapes of the hydrophobic polymer pattern, as the phase-separation of the block copolymer occurs along the deformed resist pattern.

Innovation Solution

A substrate treatment method involving the formation of a thin film on the resist pattern before phase-separating the block copolymer, which suppresses deformation during heat treatment and allows for appropriate phase-separation in a desired shape, thereby forming a predetermined pattern on the substrate.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If heat treatment is performed at high temperature to phase-separate the block copolymer, then phase-separation is achieved, but the resist pattern deforms

Engineering Contradiction:

Improvephase-separation of block copolymerVSAvoidresist pattern shape

Core Design Contradiction:

Stability of the object's compositionVSShape

Solution Approach 1:

A thin film is introduced as an intermediary layer between the resist pattern and the block copolymer. This thin film acts as a mediator that protects the resist pattern from direct contact with the block copolymer during heat treatment, preventing deformation while allowing phase-separation to occur. The thin film serves as a buffer that absorbs thermal stress and prevents direct interaction between the melting resist and the block copolymer.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The thin film is formed on the resist pattern before the block copolymer is applied and before heat treatment is performed. This preliminary action of coating the thin film protects the resist pattern in advance during subsequent high-temperature processing, enabling phase-separation without deformation of the underlying resist structure.

Inventive Principle:

Principle #10Preliminary action

2Shape

If heating temperature is decreased to prevent resist pattern melting, then resist pattern deformation is reduced, but phase-separation of block copolymer is insufficient

Engineering Contradiction:

Improveresist pattern shapeVSAvoidphase-separation of block copolymer

Core Design Contradiction:

ShapeVSStability of the object's composition

Solution Approach 1:

The thin film serves as a thermal mediator that allows heat to be applied for phase-separation while protecting the resist pattern from excessive thermal effects. It enables the system to withstand higher temperatures needed for phase-separation without transmitting the full thermal stress to the resist pattern, thus resolving the contradiction between achieving phase-separation and maintaining resist pattern integrity.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Device complexity

If block copolymer is applied directly on resist pattern, then process is simple, but phase-separation occurs along deformed resist pattern

Engineering Contradiction:

Improveprocess complexityVSAvoidpattern shape accuracy

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The thin film is introduced as an intermediary layer between the resist pattern and block copolymer. This thin film acts as a mediator that protects the resist pattern from direct contact with the block copolymer during heat treatment, preventing deformation while allowing phase-separation to occur. The thin film serves as a buffer that absorbs thermal stress and prevents direct interaction between the melting resist and the block copolymer.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

Inventive Principle:

Principle #10Preliminary action

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 method effectively prevents deformation of the resist pattern during phase-separation, enabling the formation of a predetermined pattern on the substrate using a block copolymer containing hydrophilic and hydrophobic polymers.

Implementation Method 1

a thin film for suppressing deformation of the resist pattern

Methodology Applied

Scientific EffectThermal stress resistance:

Implementation Method 2

a heat treatment is performed on the block copolymer to phase-separate the block copolymer into a hydrophilic polymer and a hydrophobic polymer

Methodology Applied

Scientific EffectPhase separation:

Implementation Method 3

By supplying an organic solvent onto the wafer, the hydrophilic polymer is selectively removed

Methodology Applied

Scientific EffectSelective dissolution: Solvation

Data Source

PatentUS20190341255A1Substrate treatment method, computer storage medium and substrate treatment system

Publication Date: 2019.11.07 TOKYO ELECTRON LTD

AI summary

A substrate treatment method of treating a substrate using a block copolymer containing a hydrophilic polymer and a hydrophobic polymer, includes: a resist pattern formation step of forming a predetermined resist pattern by a resist film on the substrate; a thin film formation step of forming a thin film for suppressing deformation of the resist pattern on a surface of the resist pattern; a block copolymer coating step of applying a block copolymer to the substrate after the formation of the thin film; and a polymer separation step of phase-separating the block copolymer into the hydrophilic polymer and the hydrophobic polymer.