Block Copolymer Self-Assembly for Nanoscale Patterning

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Solution Overview

Problem

Current block copolymer technologies face challenges in controlling the lateral placement and long-range ordering of microdomains during self-assembly, particularly for features smaller than 50 nm, and offer inadequate etch resistance for subsequent processing steps, limiting their use in nanoscale patterning and microelectronics.

Innovation Solution

A copolymer composition comprising a poly(styrene)-b-poly(acrylate) block copolymer blend with specific Flory-Huggins interaction parameters and molecular weights, combined with an antioxidant, which self-assembles into line-space patterns on substrates with pitches between 10 to 50 nm, enabling precise patterning and improved etch resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If block copolymer self-assembly is used for nanoscale patterning, then patterning resolution below 50 nm is achieved, but control over lateral placement and long-range ordering of microdomains deteriorates

Engineering Contradiction:

Improvepatterning resolutionVSAvoidcontrol over lateral placement

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The patent introduces a substrate with specific surface chemistry as an intermediary to guide block copolymer self-assembly. The substrate surface contains chemical patterns that interact with the block copolymer microdomains, directing their lateral placement and long-range ordering. This mediator enables both high-resolution patterning and reliable control by providing a template that the block copolymer follows during self-assembly.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent optimizes multiple parameters including block copolymer composition, molecular weight, annealing temperature, and substrate surface chemistry to achieve controlled self-assembly. By carefully adjusting these parameters, the system achieves both sub-50 nm resolution and reliable lateral placement control, resolving the contradiction between resolution and controllability.

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If block copolymer patterns are formed on pre-patterned substrates, then periodic micro domains are achieved, but pattern formation occurs everywhere on the pre-pattern surface causing overcrowding

Engineering Contradiction:

Improveperiodic micro domain formationVSAvoidpattern density

Core Design Contradiction:

Manufacturing precisionVSQuantity of substance

Solution Approach 1:

The patent applies local quality by creating regions of different surface chemistry on the substrate. Certain areas are made more attractive or repulsive to block copolymer microdomains, causing patterns to form selectively in specific locations rather than uniformly across the entire surface. This spatial variation in surface properties controls both periodic domain formation and overall pattern density.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent uses partial action by forming patterns only in specific regions of the substrate rather than allowing complete coverage. Through controlled self-assembly conditions and selective surface chemistry, patterns are formed in a partial manner that achieves the desired periodic micro domains while preventing excessive pattern density and overcrowding.

Inventive Principle:

Principle #16Partial or excessive action

3Ease of manufacture

If conventional lithography is used for patterning, then ease of manufacture is maintained, but feature size shrinkage is limited by light wavelength

Engineering Contradiction:

Improvepatterning process simplicityVSAvoidfeature critical dimension

Core Design Contradiction:

Ease of manufactureVSLength of moving object

Solution Approach 1:

The patent replaces conventional optical lithography (which relies on light wavelength) with block copolymer self-assembly. This substitution uses chemical and thermodynamic processes instead of optical mechanics, enabling feature sizes below the diffraction limit of light while maintaining a relatively simple manufacturing process through spin-coating and annealing.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The block copolymer system performs self-service by automatically organizing into periodic micro domains through self-assembly driven by thermodynamic forces. This self-organizing behavior eliminates the need for complex lithographic equipment and processes, achieving sub-50 nm patterning with simpler manufacturing steps while maintaining ease of manufacture.

Inventive Principle:

Principle #25Self-service

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 solution allows for the creation of highly resolved line-space patterns with smaller dimensions, facilitating the design and manufacture of semiconductor chips and other microdevices by enhancing the control over self-assembly and etch resistance.

Implementation Method 1

Some block copolymers, consisting of two or more distinct homopolymers joined end to end, are known self-assemble into periodic micro domains having typical dimensions of 10 nanometers to 50 nanometers (nm)

Methodology Applied

Scientific EffectSelf-assembly: Self-Assembly

Implementation Method 2

a poly(styrene)-b-poly(acrylate) block copolymer component, wherein the poly(styrene)-b-poly(acrylate) block copolymer component is a blend, comprising; >50 wt % to 99 wt % (on a solids basis) of an ordered poly(styrene)-b-poly(acrylate) block copolymer

Methodology Applied

Scientific EffectPhase separation: