2D Carbon Nanostructure Hardmask for High Aspect Ratio Etching

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Solution Overview

Problem

The semiconductor industry faces challenges in forming fine patterns with desirable profiles due to increased aspect ratios and etching resistance limitations in hardmask materials, particularly when using traditional lithographic techniques and existing hardmask materials, which can lead to deteriorated electrical characteristics and limited etching resistance.

Innovation Solution

A method of forming a hardmask composition using a 2-dimensional carbon nanostructure with specific oxygen content and solvent combinations, characterized by Raman spectroscopy and X-ray diffraction analysis, to enhance etching resistance and pattern formation capabilities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the height of photoresist layer and hardmask pattern is increased to handle high aspect ratio material layers, then etching capability is improved, but the hardmask pattern may be damaged during etching process and electrical characteristics deteriorate

Engineering Contradiction:
Improveetching capabilityVSAvoidhardmask integrity
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent uses a composite hardmask structure consisting of a lower hardmask layer (higher etching resistance) and an upper hardmask layer (lower etching resistance). This composite structure allows the lower layer to protect the pattern during deep etching while the upper layer prevents pattern damage, thereby resolving the contradiction between etching capability and hardmask integrity.

Inventive Principle:
Principle #40Composite materials

2Device complexity

If conventional hardmask materials are used, then process simplicity is maintained, but etching resistance is insufficient for narrow line-width patterns

Engineering Contradiction:
Improveprocess simplicityVSAvoidetching resistance
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent employs a composite hardmask structure with two distinct layers having different etching resistance characteristics. The lower layer provides high etching resistance for deep etching processes, while the upper layer has lower etching resistance to prevent pattern damage. This composite approach enhances etching resistance without significantly complicating the overall process.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent changes the etching resistance parameter by creating a gradient structure where the lower hardmask layer has higher etching resistance than the upper hardmask layer. This parameter variation allows optimization of both deep etching capability and pattern protection, addressing the insufficiency of conventional uniform hardmask materials.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If multiple layers of conductive or insulating material are stacked to form hardmask, then etching resistance is improved, but high deposition temperature modifies physical properties of material layer

Engineering Contradiction:
Improveetching resistanceVSAvoidmaterial layer physical properties
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent changes the material composition parameter by using carbon-based hardmask layers instead of traditional conductive or insulating materials. This material substitution allows achieving high etching resistance without requiring high deposition temperatures, thereby preserving the physical properties of the underlying material layer.

Inventive Principle:
Principle #35Parameter changes

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 method improves etching resistance and pattern formation, enabling the creation of high-aspect-ratio patterns with excellent mechanical strength and ease of removal, thus enhancing semiconductor process efficiency.

Implementation Method 1

it is desirable for the hardmask layer to have chemical resistance, thermal resistance, and etching resistance in order to tolerate various types of etching processes

Methodology Applied
Scientific EffectEtching resistance:

Implementation Method 2

An intensity ratio of a D mode peak to a G mode peak obtained by Raman spectroscopy of the 2-dimensional carbon nanostructure

Methodology Applied
Scientific EffectRaman spectroscopy:

Implementation Method 3

A diffraction angle 2θ of a (002) crystal face peak obtained by X-ray diffraction analysis of the 2-dimensional carbon nanostructure

Methodology Applied
Scientific EffectX-ray diffraction: X-Ray

Data Source

PatentEP2950334B1Method of forming pattern by using a hardmask composition
Publication Date: 2022.05.04 SAMSUNG ELECTRONICS CO LTD
  • EP2950334B1 patent drawingFigure 1
  • EP2950334B1 patent drawingFigure 2
  • EP2950334B1 patent drawingFigure 3

AI summary

A hardmask composition may include a solvent and a 2-dimensional carbon nanostructure containing about 0.01 atom% to about 40 atom% of oxygen or a 2-dimensional carbon nanostructure precursor thereof. A content of oxygen in the 2-dimensional carbon nanostructure precursor may be lower than about 0.01 atom% or greater than about 40 atom %. The hardmask composition may be used to form a fine pattern.