Block Copolymer Self-Assembly Template with Pinning Trenches

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Solution Overview

Problem

Current directed self-assembly methods using block copolymers face limitations in achieving high resolution and low critical dimension (CD) variation due to issues like placement accuracy and edge roughness in graphoepitaxy, and inadequate pinning in chemoepitaxy, necessitating a more effective template for pattern multiplication.

Innovation Solution

A template is introduced that includes a substrate with a neutral layer and trenches coated with a pinning material having a greater affinity for one of the block copolymer blocks, allowing for precise alignment and multiplication of patterns by pinning the blocks to the trench surfaces, thereby enhancing pattern replication and reducing self-assembly errors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If graphoepitaxy is used for directed self assembly, then pattern alignment is achieved, but placement accuracy and edge roughness deteriorate

Engineering Contradiction:

Improveplacement accuracyVSAvoidedge roughness

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

A neutral layer is introduced as an intermediary between the substrate and the block copolymer. This neutral layer prevents direct interaction between the block copolymer and the topographical features, eliminating the edge roughness problem while maintaining pattern alignment through the underlying substrate structure.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The system is segmented into distinct functional layers: the substrate provides topographical guidance, the neutral layer provides a uniform interaction surface, and the block copolymer forms the final pattern. This segmentation allows each layer to optimize its specific function without interfering with others.

Inventive Principle:

Principle #1Segmentation

2Manufacturing precision

If chemoepitaxy is used for directed self assembly, then pattern alignment is achieved, but pinning capability is insufficient

Engineering Contradiction:

Improvepattern alignmentVSAvoidpinning capability

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The neutral layer is selectively modified to create local quality variations: regions beneath the trenches maintain neutral properties while regions at the trench interfaces acquire pinning capability through the pinning material. This allows simultaneous achievement of uniform alignment and strong pinning at critical locations.

Inventive Principle:

Principle #3Local quality

3Measurement precision

If conventional lithography is used, then image exposure is achieved, but resolution is limited by diffraction and shot noise

Engineering Contradiction:

ImproveresolutionVSAvoiddiffraction and shot noise

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The block copolymer system performs self-service by automatically forming high-resolution patterns through its inherent phase separation and self-assembly mechanisms. The system uses its own thermodynamic properties to achieve resolution beyond what conventional lithography can provide, eliminating the need to overcome diffraction and shot noise limitations.

Inventive Principle:

Principle #25Self-service

4Productivity

If block copolymer self assembly is used, then pattern multiplication is achieved, but CD variation increases

Engineering Contradiction:

Improvepattern multiplicationVSAvoidCD variation

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The neutral layer creates an equipotential surface that provides uniform interaction conditions across the entire substrate. This uniformity ensures that block copolymer domains self-assemble with consistent critical dimensions throughout the patterned area, minimizing CD variation while enabling pattern multiplication.

Inventive Principle:

Principle #12Equipotentiality

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 proposed template effectively multiplies pattern density by aligning block copolymer domains with the trench features, improving resolution and reducing CD variation, as demonstrated by the comparison of annealed block copolymers with and without the pinning material.

Implementation Method 1

a pinning material in the trenches, the pinning material having a greater affinity for one of the two or more spontaneously separating blocks than for any other of the two or more spontaneously separating blocks

Methodology Applied

Scientific EffectAffinity: Adsorption