Diamond Surface Patterning via Ion-Induced Hard Mask

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Solution Overview

Problem

Current methods for patterning diamond surfaces struggle to create complex nano-scaled structures with smooth vertical side walls and high aspect ratios, requiring complex and time-consuming processes like direct Focused Ion Beam (FIB) milling or metal deposition, which are inefficient and prone to artefacts.

Innovation Solution

Exposing the diamond-like carbon surface to a low-dose He+ or Ga+ energetic ion flux to modify the material properties and create a hard mask effect, followed by oxygen plasma etching at room temperature, allowing for precise and high-resolution pattern formation without substantial material removal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If direct Focused Ion Beam (FIB) milling is used for patterning diamond surfaces, then pattern formation is achieved, but the process is time-consuming and produces artefacts

Engineering Contradiction:
Improvepattern precisionVSAvoidexposure time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent applies preliminary action by first exposing the diamond surface to a low-dose He+ or Ga+ ion flux to modify material properties and create a hard mask effect before the actual etching process. This pre-modification step enables subsequent precise etching without requiring prolonged direct FIB milling, thereby reducing total exposure time while maintaining pattern precision.

Inventive Principle:
Principle #10Preliminary action

2Shape

If conventional FIB milling is used, then patterns are formed, but complex nano-scaled structures with smooth vertical side walls and high aspect ratios cannot be created

Engineering Contradiction:
Improvevertical side wall smoothnessVSAvoidnano-structure precision
Core Design Contradiction:
ShapeVSManufacturing precision

Solution Approach 1:

The patent changes the physical and chemical parameters of the diamond surface by exposing it to energetic ion flux, which modifies the material properties at the surface. This parameter change creates a hard mask effect that enables the formation of smooth vertical side walls and high aspect ratio structures while maintaining nano-scale precision, overcoming the limitations of conventional FIB milling.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If metal deposition is used as masking agent, then pattern masking is achieved, but the process becomes complex and requires multiple steps

Engineering Contradiction:
Improveprocess simplicityVSAvoiddeposition process complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent applies self-service by using the diamond surface itself to provide the masking function through ion-induced modification. Instead of requiring external metal deposition layers, the surface undergoes self-modification when exposed to low-dose He+ or Ga+ ion flux, creating a hard mask effect that simplifies the overall process by eliminating multiple deposition and removal steps.

Inventive Principle:
Principle #25Self-service

4Loss of substance

If high-dose ion exposure is used for patterning, then material removal is achieved, but substantial material loss occurs

Engineering Contradiction:
Improvematerial removalVSAvoidpattern resolution
Core Design Contradiction:
Loss of substanceVSManufacturing precision

Solution Approach 1:

The patent applies partial action by using a low-dose He+ or Ga+ ion flux that is sufficient to modify surface material properties and create a hard mask effect, but not excessive enough to cause substantial material removal. This partial exposure achieves the desired masking effect while preserving the underlying diamond surface integrity and enabling high-resolution patterning.

Inventive Principle:
Principle #16Partial or excessive action

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 enables the efficient fabrication of sharp, precise, and high aspect ratio three-dimensional nano-scaled patterns on diamond surfaces with significantly higher resolution and shorter exposure times compared to conventional FIB milling, while avoiding common artefacts associated with large-area milling.

Implementation Method 1

exposing part of the diamond like-carbon based surface to a He+ or Ga+ energetic ion flux to modify the material properties and create a hard mask effect

Methodology Applied
Scientific EffectIon implantation: Ion Implantation

Implementation Method 2

etching unexposed parts of the surface to form said structures, wherein said step of etching uses a plasma

Methodology Applied
Scientific EffectPlasma etching: Plasma

Data Source

PatentEP3276418B1Process and system for fabrication of patterns on a surface
Publication Date: 2020.09.09 THE PROVOST FELLOWS FOUNDATION SCHOLARS AND THE OTHER MEMBERS OF BOARD OF THE COLLEGE OF THE HOLY AND UNDIVIDED TRINITY OF QUEEN ELIZABETH NEAR DUBLIN
  • EP3276418B1 patent drawingFigure 1~2
  • EP3276418B1 patent drawingFigure 3A~3B
  • EP3276418B1 patent drawingFigure 4

AI summary

The invention provides a system and process of patterning structures on a carbon based surface comprising exposing part of the surface to an ion flux, such that material properties of the exposed surface are modified to provide a hard mask effect on the surface. A further step of etching unexposed parts of the surface forms the structures on the surface. The inventors have discovered that by controlling the ion exposure, alteration of the surface structure at the top surface provides a mask pattern, without substantially removing any material from the exposed surface. The mask allows for subsequent ion etching of unexposed areas of the surface leaving the exposed areas raised relative to the unexposed areas thus manufacturing patterns onto the surface. For example, a Ga+ focussed ion beam exposes a pattern onto a diamond surface which produces such a pattern after its exposure to a plasma etch. The invention is particularly suitable for patterning of clear well-defined structures down to nano-scale dimensions.