Block Copolymer Self-Assembly for High Aspect Ratio Pattern Formation

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Solution Overview

Problem

The increasing integration density of semiconductor devices leads to decreased reliability due to deteriorated deposition and etch processes, particularly with narrower pattern widths and higher aspect ratios, which affects the distribution and accuracy of thin film processes.

Innovation Solution

A method involving the use of block copolymer materials, such as polystyrene-block-polymethylmethacrylate (PS-b-PMMA) or polystyrene-block-polydimethylsiloxane (PS-b-PDMS), where mask patterns are formed on an etch target layer, filled with the block copolymer, and annealed to create specific patterns that act as etch masks for forming reliable pattern structures with improved integration density.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If integration density is increased, then device functionality and capacity are improved, but deposition and etch process distribution deteriorates

Engineering Contradiction:

Improveintegration densityVSAvoiddeposition and etch process distribution

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies segmentation by dividing the pattern formation process into multiple steps using block copolymer self-assembly. The block copolymer is segmented into different polymer blocks (e.g., polystyrene and polymethylmethacrylate) that spontaneously separate into distinct domains, enabling precise pattern definition without relying on traditional deposition and etch processes that fail at high integration densities.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent changes the physical and chemical parameters of the patterning process by using block copolymer materials with specific properties. By controlling parameters such as polymer block composition, molecular weight, and annealing conditions, the method achieves precise pattern formation at dimensions where conventional deposition and etch processes cannot maintain distribution and reliability.

Inventive Principle:

Principle #35Parameter changes

2Productivity

If pattern width is decreased, then integration density is improved, but deposition and etch process reliability decreases

Engineering Contradiction:

Improveintegration densityVSAvoiddeposition and etch process reliability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent employs self-service by utilizing the self-assembling property of block copolymers. The block copolymer material automatically organizes itself into periodic patterns through phase separation of different polymer blocks, eliminating the need for external deposition and etch processes to define patterns at nanoscale dimensions. This self-organizing mechanism ensures reliability without relying on deteriorating conventional processes.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent exploits phase transitions by heating the block copolymer layer above its glass transition temperature during annealing. This phase transition enables the polymer chains to move and reorganize into equilibrium self-assembled structures, creating reliable and precise patterns at dimensions where traditional deposition and etch processes fail to maintain reliability.

Inventive Principle:

Principle #36Phase transitions

3Shape

If aspect ratio is increased, then vertical structure capability is improved, but deposition and etch process distribution worsens

Engineering Contradiction:

Improvevertical structure capabilityVSAvoiddeposition and etch process distribution

Core Design Contradiction:

ShapeVSManufacturing precision

Solution Approach 1:

The patent transitions from two-dimensional planar patterning to three-dimensional vertical self-assembly by forming block copolymer patterns that extend vertically with high aspect ratios. The self-assembled block copolymer structures naturally form upright cylindrical or lamellar domains that provide excellent vertical sidewalls, enabling high aspect ratio structures without relying on deposition and etch processes whose distribution deteriorates with increased aspect ratio.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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 approach enhances the reliability and integration density of semiconductor devices by allowing precise pattern formation and etching, overcoming the limitations of traditional deposition and etch processes, and enabling the fabrication of patterns with critical dimensions suitable for advanced photolithography and double patterning technologies.

Implementation Method 1

annealing the block copolymer material to form first patterns and second patterns, the first patterns in contact with facing sidewalls of adjacent ones of the mask patterns, respectively, and at least one of the second patterns between the first patterns

Methodology Applied

Scientific EffectPhase separation: Phase Change

Data Source

PatentUS10854465B2Method of fabricating pattern structure

Publication Date: 2020.12.01 SAMSUNG ELECTRONICS CO LTD

AI summary

A method includes forming mask patterns spaced apart from each other by at least one opening on an etch target layer, filling the opening with a block copolymer material including first and second polymer blocks of different properties, and annealing the block copolymer material to form first patterns and second patterns, the first patterns in contact with facing sidewalls of adjacent ones of the mask patterns, respectively, and at least one of the second patterns between the first patterns. The first patterns include the first polymer blocks and the second patterns include the second polymer blocks.