Self-Assembled Block Copolymer Domain Placement Analysis

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Solution Overview

Problem

Current self-assembled block copolymer layers in lithography exhibit high defect rates and poor uniformity in domain placement due to weak intermolecular interactions, limiting their effectiveness in achieving precise nano-scale feature resolution.

Innovation Solution

A computer-implemented method using image analysis to detect features, determine critical dimensions, and fit periodic curves to assess placement errors in self-assembled block copolymer structures, enabling accurate evaluation of pitch and periodicity for improved domain alignment and defect identification.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If self-assembly of block copolymer is used to form nanometer-sized domains, then resolution is improved, but defect rate increases and domain placement uniformity deteriorates

Engineering Contradiction:

ImproveresolutionVSAvoiddomain placement uniformity

Core Design Contradiction:

Measurement precisionVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by pre-patterning the substrate with alignment marks and guide structures before depositing the block copolymer. This pre-structured substrate template directs the self-assembly process to form domains with controlled positions and orientations, reducing placement defects and improving uniformity while maintaining nanometer-sized resolution.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent introduces an intermediary layer or modified substrate surface that mediates between the block copolymer and the substrate. This intermediary structure provides specific interaction sites that guide domain formation, acting as a template to control domain placement precision while allowing the self-assembly mechanism to maintain its resolution advantages.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Measurement precision

If self-assembly of block copolymer is used to form nanometer-sized domains, then resolution is improved, but defect rate increases

Engineering Contradiction:

ImproveresolutionVSAvoiddefect rate

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent incorporates feedback mechanisms through post-deposition analysis methods that detect and characterize domain placement accuracy. This feedback information is used to optimize the self-assembly process parameters and substrate patterning designs, iteratively reducing defect rates while maintaining high resolution.

Inventive Principle:

Principle #23Feedback

3Ease of manufacture

If conventional lithography is used, then manufacturing process is simpler, but feature size reduction is limited

Engineering Contradiction:

Improvemanufacturing process simplicityVSAvoidfeature size

Core Design Contradiction:

Ease of manufactureVSLength of moving object

Solution Approach 1:

The patent applies segmentation by dividing the patterning process into two stages: first creating a coarse pattern through conventional lithography, then using self-assembly to segment this into finer nanometer-sized domains. This multi-scale approach maintains the simplicity of conventional lithography for the first stage while achieving much smaller feature sizes through the self-assembly process.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent replaces the mechanical limitation of conventional lithography (diffraction limits) with a chemical self-assembly mechanism. Instead of relying on optical or electron beam mechanics that are size-limited, the process uses molecular self-assembly to achieve nanometer-scale features, effectively substituting a physical constraint with a chemical process that operates at smaller scales.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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

This method significantly reduces defect rates and improves domain placement accuracy, enhancing the uniformity and precision of nano-scale features in lithographic patterns, thereby meeting stringent specifications for critical dimension uniformity and placement error.

Implementation Method 1

A self-assemblable block copolymer is a compound useful in nanofabrication because it may undergo an order-disorder transition on cooling below a certain temperature (order-disorder transition temperature TOD) resulting in phase separation of copolymer blocks of different chemical nature to form ordered, chemically distinct domains

Methodology Applied

Scientific EffectOrder-disorder transition: Phase Change

Implementation Method 2

phase separation of copolymer blocks of different chemical nature to form ordered, chemically distinct domains

Methodology Applied

Scientific EffectPhase separation: Phase Change

Implementation Method 3

The use of self-assembly of a block copolymer (BCP) has been considered as a potential method for improving the resolution

Methodology Applied

Scientific EffectSelf-assembly: Self-Assembly

Data Source

PatentUS9367910B2Self-assemblable polymer and methods for use in lithography

Publication Date: 2016.06.14 ASML NETHERLANDS BV

AI summary

A method and system to analyze various dimensional parameters of a structure, such as a self-assembled block copolymer structure whether formed by graphoepitaxy or chemical epitaxy. The method involves image processing including median filtering and feature detection to determine critical dimension information, and optionally the use of a Hough transform to find periodicity values and to determine placement errors.